WIP A Distant Galaxy

[Gidde]

Science fiction worldbuilding depends heavily on how "hard" you want the sci-fi ... as in how plausible you want the science. If you want it really plausible, the best way to do it is to look at actual science and take some intuitive (and fictional) leaps.

If you have a library nearby or can spare the cash to buy it, Orson Scott Card wrote an invaluable book about how to handle all of the things you're talking about. If not, here are a couple links to get you started (these are all places I've gotten good stuff for the sci-fi I'm researching). A google search on "science fiction worldbuilding" should yield some good results too.

Fantasy Worldbuilding Questions (fantasy and sci-fi intermix alot, so still useful)
Interstellar Travel on Wikipedia (and pretty much everything under See Also)
Universe Today is a great site for the actual science of space as it stands now
Space Cynic will give you an idea of what the problems with different space ideas are, so that you can deal with those problems in your world.

[Uomaru]

Thanks for the reply! I think I'm going for a more space opera-ish feeling, something along the lines of Mass Effect and Halo (not sure of Halo's genre). I've mostly been playing around with fantasy ideas and concept, so I'm new to SF. If I would focus on a Hard science fiction setting it will just turn out bad... really bad. Accuracy and mathematics are not my strong side

Preferably I want to focus on how it would be if humans, out of pure desperation and near extinction, invades another galaxy. What could possibly be the outcome and the consequences of the humans actions?
I also want to focus, as in my previous post, on governments and oraganizations, aliens and their culture and similiar stuff like that Hopefully it will turn out good!

[Hai-Etlik]

If you are willing to spend a bit of money, GURPS Space is a quite impressive collection of material: Interstellar societies and technology, Placing worlds within a galaxy, designing worlds and star systems, and designing alien life. You don't need the rest of GURPS to use it.