Complete Newbie Help!

[Toastedkl]

Hey guys,
I am thinking about installing my system myself... eventually. However, I have NEVER done it before! OK I know, not a great start, but I really want to learn! I've got a Yaris Hatchback (5 dr) and don't want to do a boring parcel shelf install (even though the parcel shelf is too small anyway!) What I want to do is put the sub in the spare tyre, get a new headunit, and install new speakers in the door. I have a couple of questions for you guys. Do know of any good resources (ie. books, internet...) of an absolute, easy to follow, beginners guide of how to install stuff, with everything from installation to the description of what everything means. Could anyone spill the beans for with me? Another Q is that can I install a 12" sub with Coaxial speakers (obviously with a new headunit)? I've got around £600 to do it. Not mega bucks but looking to upgrade in time!
Thanks if anyone can help!