Welcome to the Warhammer: Invasion Rules forum.
If you've just picked up the game and have some questions, make sure you have the most current version of the Rulebook and FAQ. They answer a lot of questions, and have some key changes from the original rulebook (particularly how combat damage is assigned). You can find a an official PDF of the rulebook here , and an official copy of the latest FAQ here .
If you want an unofficial, condensed, printable rulebook, you can find one here . It's a condensed and reorganized compilation of the rulebook and the official FAQ, with bookmarks to help you quickly navigate to the section you need.
If that doesn't answer your question, try the unofficial Rules Summary , maintained over at deckbox.org. That site maintains a database of every W:I card out there, and the forums allow you to create mouseovers of the card image, very helpful when you're learning the game and don't know the details of all the cards everyone is talking about. The Rules Summary is a searchable list of all the major card questions that have been asked and officially answered by FFG (many of which are now in the FAQ as well).
If you still can't find an answer, make a post in the forum, preferably with the card(s) in question in the title. One of the many players who frequent this forum will generally answer pretty quickly. You won't get an official response from FFG, these forums are just for players to talk to each other, they only moderate them to keep everyone civil.
If that still doesn't satisfy you, you can also submit the rules question directly to FFG using the " Rules Question " link at the very bottom of the page. Keep in mind that answering those questions is just one small part of one person's job at FFG, so trying to find the answer yourself will help them cut down on overhead and keep cranking out new content and official rules updates.