If you're buying ETFs and Stock you should wait until have you a large sum saved, then invest it. Depending on your brokers you're paying $10+ a trade.

That means you have to earn 2%, just to break even.

If you're going to invest small amounts of money (dollar cost averaging, the best way to do it in my opinion), I would suggest a low cost mutual fund. Most mutual funds have no transaction fees. Check with your broker, I bet they have an index fund that has an expense ratio of less than .5%.

As Rick said above. You shouldn't own stocks unless you spend a lot of time researching everyday.