There is no guarantee you'll make ANYthing. If when you sell, someone is willing to pay more than you bought it for, you make the difference, less the broker commissions.
Contact Fidelity or Scottrade or one of their fine competitors.
How much money will you make off that stock? Based on your current stock market knowledge, I would guess you lose all that you "invest".
If I want to buy stock in something, how do I go about doing that? Could I do it just by filling out paperwork myself and submitting it, or do I need to have a professional do it? Also, how much money would I make off that stock? Is there a set percentage for all stock prices that can be used to determine that?