This website contains everything handy for sci-fi from the basics of rocketry, trough specifications of engines to the discussion of weapons and aliens. The website also contains a large bundle of links for further information.
The website is not entirely fabrication, in fact it aims to be the least fictional ever. It gives specifications and links to NASA project NERVA/KIWI, real nuclear-powered rockets that NASA experimented with. It also discusses lasers as weapons and finds that a few functions of Star Trek's phasers can be mimicked.
http://www.projectrho.com/rocket/index.html
