Since I'm trying to create a purely Guardsman Campaign and having played GURPS recently I thought we could add the Soldier skill to the Guardsman skill package (thus granting him 3 skills instead of the staggering 2).

Guardsman (Int)
These are the lessons a soldier learned at boot camp and those he read in the Imperial Infantryman’s Uplifting Primer.
It tells him how to fieldstrip his rifle and where to dig his foxhole, where the mess should be and when he should wash himself.
The GM may allow a player with this skill to make a Hard (-20) Guardsman Skill Test whenever he doesn’t have the appropriate skill but would have picked up this knowledge during basic training.
This test may be modified depending on the difficulty of the task ahead.

A second thing I would like to introduce are 8/9 skill and talent package to which a player may have access (but only one).
So far I have:

Rifleman
Sapper
Designated Marksman
NCO

As a third I will introduce a sort of General Skills package so in a Campaign where only one career is permitted people can specialise and take more Social Skills than normally allowed.

Any more tips and hints?

My approach to this is that if somebody could know something because of his career or background, I just allow them a Test on Intelligence (Challenging, Ordinary, Routine or Easy).

This method was used in "Black Sepulchre" as well (as it was mentioned that a Feral Worlder might recognize something that he might have encountered one way or another at this homeworld).

Okay, version II

Guardsman (Int)
These are the lessons a soldier learned at boot camp and those he read in the Imperial Infantryman’s Uplifting Primer.
It tells him how to fieldstrip his rifle and where to dig his foxhole, where the mess should be and when he should wash himself.
The GM may allow a player with this skill to make a Challenging (+0) Guardsman Skill Test whenever he doesn’t have the appropriate skill but would have picked up this knowledge during basic training.
This test may be modified depending on the difficulty of the task ahead but should always be more difficult than the original skill that would have been used.

For example:
Finding fruit in the Jungle would normally be an Ordinary (+10) Survival Test, so the GM allows the Guardsman to make a Challenging (+0) Guardsman Test, if the Survival Test would have been Challenging (+0) the Guardsman Skill Test should at least be a Difficult (-10) Test.

Santiago said:

Thinking maybe there should be a "Trade- Military" skill perhaps with some sub-sections like Imperial Guard, PDF and Navy?

Sort of a catch-all for the various fieldcraft, rank insignia, where not to stand behind the artillery piece, who to ask for more ammo and why you should avoid the guy with the hat, flack coat and bolt pistol. Later on when you've got it at +10 or 20, it'd also cover things like armoured divisions (what tank is that) drop troops (fall out of a what where?) and who to see about trading your supplies for some that you actually need.

MKX said:

Isn´t their a Common Lore skill for it already? I might be mistaken here, so.

True, think it would be covered under common lore - imperial guard

I really think to cover skills that you didn't really learn but could know something about the idea of basic skills was invented.
So if you think there are skills that a soldier could have basic knowledge in without having learned it, just give him that skill as basic skill.

Does not knowledge always have to be learned? I think what you mean might be the ability to roll one's half characteristic on a basic skill because the character attempts to guess or piece together parts of what he has heard somewhere, without actually being sure or ever having had the chance to learn about that specific case.

Survival is normally an advanced skill. Just make it so that a Guardsman can treat Survival as a basic skill, meaning even if he did not purchase it, he can still roll 50%. We have such cases in the RAW already.

For the Uplifting Primer, having that book at hand could confer a +10 or +20 bonus to the appropriate skill tests (we have examples for this in the official books, too) whilst extending the duration of the action as the character has to read up on stuff whilst performing it.

PS: Also remember that the Imperial Guard doesn't work like a contemporary military. They do not really have boot camps - they pick you up as part of your homeworld's tithe, then you are immediately shipped to wherever you are needed. Training lessons are done whilst in warp transit and are thus (in most cases) far less extensive than proper training. You may have had PDF bootcamp before you got drafted for the IG, but that's neither guarenteed nor in any way uniform. Some PDFs still do line combat etc, after all.

That said, there are cases where a DH Guardsmen can be a veteran (the books are somewhat vague on this subject), so specialized knowledge could be part of an appropriate background package to denote what the character in question has learned from previous encounters, even if his original training sucked.

Lynata said:

Incorrect. It is, as described in Codex: Imperial Guard, standard practice when raising Regiments of Imperial Guard to take at least 10% (and as much more as the Departmento Munitorum requires) of the world's military - the military that every world is obliged under Imperial Law to raise and maintain - and the Imperial Commander's life is forfeit should the soldiers he offer up be of insufficient quality.

Every Guardsman, except in extreme circumstances (that is, when drafting from existing armed forces alone is insufficient to provide the required numbers) is a trained soldier in some way, shape or form, and will have been for some time before becoming an Imperial Guardsman. They won't be particularly uniform (that's what training post-draft is for), but they'll be soldiers.

As Lynata stated correctly, Imperial Guardsmen are draw from each planet's PDF the top pedrcentage as required, but final Imperial Training is done on route to the relevant warzone. So training would vary widely, it is a good idea to discuss the background of the guardsmen in question rather than throwing in another skill that is mostly covered by Common Lore (War) or Common Lore (Imperial Guard).

Valdek said:

Lynata said, and I quote, that an individual guardsman "may have had PDF bootcamp" before being drafted into the Imperial Guard, which more than implied the common misconception that most Imperial Guard are witless conscripts who barely know which end of the lasgun does the killing.

My correction was that the overwhelming majority of Imperial Guardsmen would have a noteworthy degree of basic training, rather than being a vague possibility. This is then built upon where necessary with intensive training and re-education (both mentioned in the current Codex) in transit, a journey that may take many weeks or even months of subjective time (that is, time from the perspective of those on board a vessel in the Warp, as opposed to the time passed as observed by those not in the Warp)... I say where necessary, because the likes of highly militarised and/or industrialised worlds (Cadia, Krieg, Armageddon and Necromunda being the best examples) tend to produce PDF forces that are Imperial Guard in all but name, and I don't imagine that such an approach is all that uncommon across the Imperium (indeed, I imagine that the Departmento Munitorum encourage it, as it makes their job easier), especially given that militarised/industrialised worlds will typically have large armed populations from which to draw Regiments from, and thus will collectively produce an overall majority of the Imperial Guardsmen within the Imperium at any one time.

"May" implies that a tithed soldier may have received PDF training, or he has not. Nothing more, nothing less.* What's way more important is that this training will obviously be different from world to world and not conform to any standards that apply to the Munitorum. The soldiers drafted from a planet will have their own equipment and, more importantly, their own fighting style, which ranges from medieval cavalry tactics to 17th century line combat to modern day small groups tactics. There will be many cases where, whatever training a soldier has received before, much of it will be rendered worthless by the sheer need to have them re-learn the essential basics covered in the Primer.

And given that the survival skill was already mentioned in this thread: Depending on the skill you are looking for, these differences may also originate simply from the homeworld's environment; e.g. you should not assume that a Guardsman from a unit raised on a desert world knows how to survive in a jungle. Allowing him to roll 50% should be enough to represent the aforementioned basics.

(*: As an example, we know that entire gangs from hives get drafted for the IG, and I doubt that these have been members of the Planetary Defense Force before)

With regards to PDF forces bing drafted into the IMperial Guard, the Novel "15 hours" offers some insight into that as well, in my opinion. Even though there are some things that don't go as planned for the Guardsmen during their deployment in that novel, it describes one way of transitioning from PDF to IG rather well, in my opinion. I don't have the bood with me right now, so i can't give any more sepecific details.

As much as I (nowadays) insist that novels cannot establish canon by themselves, this one is actually a book that I was planning on getting either way ... so thanks for making me even more curious!

This forum does a good job at recommending books.

Common Lore (Imperial Guard, War) cover everything that you are looking for and much, much more.