My friends and I just started playing, but we can't seem to find an answer to this:

When we enter a new system, how do we colonize a new planet and bring it under our control? will the control tokens work, or do you have to land troops?along those lines, when you enter a new system and there is more than one planet, can you colonize both in the same turn? Along those same lines, once you do have control of the new planets, do you get them tapped or untapped?Finally, answering the previous question, how much does it cost to build a space dock in the new system? none of the cards seem to answer that question!

TL;DR at end of post

Within the Tactical Action there are basically three parts: Movement, Combat and Building. They always happen in that order.

The second half of the Combat part is when you colonize/invade planets, the aptly named Planetary Landing step. During this step the active player decides how many troops (Infantry, also known as Ground Forces to those familiar with 3rd ed.) they wish to land on each of the planets (a system has 0-3 planets and all can be taken over in the same turn.) in the active system.

After any Ground Combat (Which must be initiated if another player already has troops on the planet in question) the player who landed units immediatley gains the card for that planet in an exhausted (tapped) state.

As for the cost to build a Space Dock, this has changed drastically from 3rd edition. There is no cost associated to the Space Dock because it , along with the PDS unit, is now constructed via either the Primary/Secondary of the Construction Strategy Card or one(?) certain specific Agenda or Action card.

TL;DR: Must land units to take planets, can take all planets in the same turn, get planet(s) tapped and must use Construction SC to build Space Dock (or PDS).