First of all, welcome!
I'm trying to stay on topic here and avoid the arguments so here's what I have to say:
1. I started out by using just random decks, both plastic and paper. I used plastic decks, very thin, and smaller than regular Bikes, but I switched after finding difficulty in some maneuvers. After a while, you kinda have to get used to the norm, which for me are Bicycles. Since you're just starting out, there's really no need to get fancy decks, unless of course you want to. Bikes for me are already suitable enough, for practice and even for performance. It's very much comparable to other decks out there and they're quite versatile. Also, try to get used to using them, poker size too, since these are widly used and very common.
2. Sleights are basically "the moves". They're what you do to accomplish the effects. Lifts, passes, changes, palming and many others. Definitions of these, how to do them, and the different sleights, are too many to mention. Of course, the more basic ones can be found in one of the sources said by the posters above. Get them down. Start with the simpler ones, like grips and lifts. I used to think grips were not very important but actually, they are.
3. I started out with tricks that came from ordinary magic books. They were not very popular and I just found them in the libraries. The first tricks I learned were self working and didn't require too much sleights. You got to start somewhere right? Find ones that are easy to do, then work your way towards the more complicated tricks. You'll develop your skills gradually, so don't worry about it.
That's it for now. Any more questions, just ask. Good luck to you!