If you didn't take advantage of those big tax credits for energy-saving home improvements in 2010, you have another chance in 2011. Although smaller than last year's offerings, credits remain on the federal tax books.

Homeowners can claim up to 10 percent ($500 maximum) on eligible projects in 2011. Last year's federal credits were three times higher. Some states have additional credits, as well. (For a list of your state's tax credits, visit the DSIRE website.)

At least seven energy-saving home projects are available for federal tax credits this year. They include upgrades to heating and air conditioning systems, roofs, insulation, windows and doors.

If you're unsure of where to start to make energy-efficiency improvements to your home, consider hiring an auditor to identify the energy hogs. Some utility companies offer rebates for professional energy audits; others offer the service themselves. Generally speaking, the biggest energy drains in most homes are air conditioners, large appliances and water heaters.