I have a few question if anyone would be as nice to answer it for me and explain please.

1) Is it as simple as people buying stocks that cause the price of the stock to go up? If so is there a formula to predict if you buy a certain amount of stocks how much the price of the stock would be?

2) What online place do you think is the best one for online trades. EXample i have sharebuilder and its crappy because alot of the stocks I want they dont offer.

3) Also is there a site that gives you a list for FREE of stocks under $3 to invest in.

4) And finally i have been reading up on here about ob shares or what ever it is called but what makes them different from other stocks?

Sorry for so much questions but i am a college student and in a week i wont have alot of time to sit on the computer and buy and sell my stocks. FYI i only have 2,000 to invest right now. Should i even be trading?