A lot of good advice in here.
My suggestion- which has been stated- is learn as much about investing as you can before you start and think out what you do. What works one person, may not work for you. Unless you know every nitty-gritty detail that they know, you're still shooting at a dart board. And unless you invest and pull out exactly what and when they do, you won't get the same results.
Example 1: Someone suggested getting financial advice. That's not profitable for me. With a live-in GF that has two kids, a third on the way, a newly purchased money-pit (house), and my low salary (23 w/o a degree), it would take forever to get the advice fees back with my investment.
However, I'm not looking to get rich. I'm just looking to get a better ROI over the next several years than I presently do with CD's, bonds and MMA's; and not pay a fortune for commission (enter sharebuilder). So, for me, with all things considered, index ETF's are my friends. Again, simply opinion, I prefer "market" indexes to "sector" indexes (enter S&P 500, EAFA, etc. index funds).
Example 2: Until I bought the house I never bought stock, funds, or bonds. I always picked up CD's and had an MMA (money-market account).
Why? Because it wasn't worth it. I planned on buying a house in a few years as well as paying for my education, so I couldn't afford the risk. Now that dream's a reality (with cash left over) I can look at longer term and potentially more profitable investments.
But, like I said, take my approach for what its worth... Nothing unless you look, learn, think and understand for yourself. And when you do, you'll understand that the hardest thing isn't all the mumbo-jumbo financial stuff (which most of it is trivial anyway); but actually having the discipline to save and consistently contribute money.