^ What I found helpful before playing the old X-Com was check out an "let's play" on the youtubes. May be just me, but I do learn faster seeing the UI used in context rather than than trying to memorize an instruction manual.
Incidentally, I think Steam often has PDFs of manuals available to download, just by right clicking the game in your library. Not sure if it's all games, or even any of the older games at all. Good place to start though.