Mocus pretty much hit the nail on the head. Remember this though....domains are an investment....with every investment comes risk. You can do lots of research to minimize your risk, but chances are, you will buy some stinkers. Imagine this....you buy 15 names......10 of them end up being duds and never make the first dime in traffic....you have only spent $108 total. BUT....now imagine that the other 5 make $50/each per month....now you are talking $250 X 12 months...= $3,000 a year...minus $108 = $2892. Not a bad return off of a $108 investment. In fact...we are talking almost a 2,700% return. Good luck making that in the stock market!
You can also look for expiring names with OVT w/extension. This can be very pricey though. I do what Mocus does...and I find websites and then type them in really fast and see what mistakes I make. If I am doing that typo...chances are someone else is as well.
Recently, I have been looking for new sites that have only been out a few months but are moving up the charts quickly. I have been trying this technic for a few weeks....we'll see what happens in the next few months.
Best of luck...and if I can help, I will. Feel free to PM me. I am currently workjing on a website that will teach beginners how to do all of this stuff. My plan is to help keep people from wasting as much money as some of us have. hehehe. You will learn alot on DNForum.
Take care
//everydayprofit