I'm planning to begin running the Haarlock's Legacy campaign for a group of my friends and was looking for any advice or insight people here would be willing to give.

Moreover, I know House of Dust and Ash is loosely connected, should I run it first? Are there any other adventures connected to the campaign that I should run either before or after?

Its been a while since I GM'd a game of Dark Heresy though I have been playing it in the interim. So knowing the above would be most helpful.

I haven't run it myself, but I'm pretty sure House of Dust and Ash should come first. Also, I've heard people here on the Forums say that Damned Cities - the second in the series- actually works better if played before Tattered Fates . -And I assume you've seen this thread about the Legacy:

http://www.fantasyflightgames.com/edge_foros_discusion.asp?efid=101&efcid=3&efidt=277689

Ive seen that thread, but have yet to read it in it's entirety. Probably gonna do that soon.

There is some reworking that is needed so that the PCs don't feel so ....ummmm.... "led by the nose". Throw in some other things to adventures that connect with an over all adventure that you are running....I used the Haarlock series as sort of a stop over spaced out between sessions not just one right after another. I also didn't make in the main adventure focus.....even though at the end there can be a game changing event ....Also that event is approached in the wrong way IMO. It should be a little more difficult then moving some dirt .

Other than that my group is having a good time with it.....all it needed was some adding to

The Harlok campaign can be fun , but as others have stated alot of extras should be added to make it challenging and enjoyable. I would take some main points out of the 3 books and add clues in some of the earlier modules, or just make your own to give it more of a grand scope. I had started this campaign a long while ago, but then Deathwatch came out and my group wanted to play that so I have switched gears. As far as other modules go you could use some from Purge the Unclean or even the ones in the back of the rescource books and easily add a few changes to give you some basis.