If you have a full-time job and it's not picking stocks, acknowledge that. Choosing three or four index funds - say, an S&P 500 fund, an EAFE fund, and a small-cap stock fund - will give you broad exposure. ETFs (low-cost mutual funds that trade like stocks) are also an easy way to invest in more exotic asset classes, like commodities. If you're close to retirement, consider life-cycle funds from Vanguard or T. Rowe Price, which will automatically rebalance your account according to your goals.