(MONEY Magazine) – More than 4 million sites provide free advice, but up-to-date listings will cost you. In general, stay away from sites that don't offer free trials. --CAROLYN BIGDA

Foreclosure.com More than 51,000 properties updated twice daily. REOs, HUD, Fannie Mae and VA homes. Price: $23.80 a month.

Foreclosures.com Not to be confused with Foreclosure.com. No free trial. Pre-foreclosures in the Southwest, the Chicago area and the Northeast. Listings updated daily or weekly. Price: $30 to $79 a month.

RealtyTrac.com Trustee sales, auctions, pre-foreclosures and REOs. Some pre-foreclosure data can be up to a week old. Outlines state laws and types of foreclosures by state. Detailed property reports at additional cost. Price: 24.95 a month.

WilliamsAuction.com The largest real estate auction company in the country. Advice, auction schedules and photos. REOs only. Free.

Nationalreia.com/groups.htm No-frills site allows you to find local real estate investing clubs; useful for tutorials and tips. Free.

HUD.gov/homes Info on HUD properties. Online auctions. Clear instructions for first-time buyers. Free.

FirstGov.gov/shopping/realestate/realestate.shtml Government properties including IRS, VA, Fannie Mae, Freddie Mac. Free.