Many employer retirement plans will automatically enroll you in a plan, typically at a contribution rate of 3 percent to 6 percent of your salary. That's a good place to start if it at least equals the maximum rate your employer will match. But don't get too comfortable at that level, or with the plan's built-in increases.

Lane says most people need to save 10 percent to 15 percent of their income for retirement, and she notes that some financial planners tout 20 percent as the target amount.

Stuart Ritter, vice president and Certified Financial Planner with T. Rowe Price Investment Services in Baltimore, advocates saving 15 percent.

"If your employer is bringing you in at 6 percent and increasing you by 2 percent a year, it's still going to be a number of years before you get to 15 percent," Ritter says. "The sooner you get there, the better off you're going to be."