Step 7: Relax. If you don't borrow money and you do just buy a handful of shares of something you understand with what little you can afford to play with, relax. When markets are down, relax. Unlike people who let a professional talk them into going into debt to buy portfolios that looked bigger than yours, you don't lose anything when markets are down. If you understand what you're invested in, and you understand that it should go back up, buy another handful of shares with however little you can afford to play with. Enjoy the ride when it goes back up. Sell when it feels high enough and you need cash. If you're not borrowing money to do this and your gains aren't being eaten by interest and fees, it really doesn't matter if you're not perfectly timing the exact highs and lows down to the penny.
Regardless of whether you go for stocks, mutual funds, or CDs, this point is something to remember. Put money into things, then forget you have it, and be pleasantly surprised later when you go to see how much is in there. Admittedly this applies more to the latter two as stocks can go negative, but if you forget you have it, you won't be tempted to spend it, pull it out early, or stress out about if it's going up or not.
Another thing to consider if you go into stocks is looking for stocks that pay derivitives. Those give you money regularly based on how the company is doing, rather than just the theoretical value of the stock that you have to sell to realize.