In today's edition of "Ask a Fool," Fool retirement guru Robert Brokamp is asked: "Asset allocation, how much of my portfolio should be in stocks, fixed income, etc.?" Robert provides a few retirement rules of thumb about how investors should adjust their portfolios as they age to match both their risk tolerance and investment goals. He provides a few no-nonsense portfolio-allocation strategies you can apply for years to come.

As Robert mentions, every portfolio should have at least some of its assets in stocks, regardless of your age. If you're stuck about which stocks to pick for that section, you can start by reading our report: "3 Stocks That Will Help You Retire Rich." In it, you'll learn about three incredible wealth-building stocks for the long haul.