Do you have a pension plan that allows you to decide how you distribute your savings? Does you job offer any matching contributions? If you can save 15-20% of your net and put it toward something with a guaranteed return (3-5%), time will be on your side. By the time you're ready to retire, you'll be fine -especially if you start young. There are lots of good funds, but it really depends on how much you're willing to risk and for how long (i.e., whether you plan on using it in the near future).
You should probably look at some guides to investing on Forbes magazine site or Businessweek. I've always used automatic paycheck deductions and transfers to mutual funds. You can check the ratings for individual funds using Google. But, imo, the key is to think long terms. In theory, the younger you are, the more risk you can afford --as long as you make continuous contributions.
Of course, the younger you are, the more likely you will want to spend your money, especially extra money.
"A man is rich when he has time and freewill. How he chooses to invest both will determine the return on his investment."