I see the markets have had a run. I've been on the sidelines and wonder if it's too late to start investing. Should I wait for a pullback in the market? — Joshua R.

Your chances of timing the market successfully are somewhere between slim and none. "Even the best advisors with the best computers can't do it," says Jason Lampert of New York City-based MTP Advisors. His suggestion: Adopt an investment strategy based on steady investing, not market timing.

Academic research on the subject indicates that the most profitable strategy, on average, is to go all in: If you're going to put a pile of cash in the market, do it all at once. But given your uncertainty about investing, that might not be a realistic plan, psychologically speaking, for you. You're better off dipping your toe in the water and slowly sliding into the market rather than leaping off the high dive.

The best way to do this is by investing a set amount of money on a regular schedule, a strategy known as "dollar-cost averaging." With DCA, you are more likely to avoid buying at the peak of the market. Even better, your regular investments will help you continue to invest even during market downturns, when investments are cheaper.

Meanwhile, Lampert says that while you can't control the market, you can control how much you pay in investment fees. He recommends low-cost ETFs and broad market index funds, which offer diversified portfolios without breaking the bank.

— Austin Kilham