The alphabet soup of Medicare's various plans can be a puzzle. But several free handbooks will teach you the ABCs . . . and the D's to N's, too.

Those confused about the differences between Medicare and Medicaid should download "The Essentials: Medicare and Medicaid," a 40-page booklet from MetLife Mature Market Institute. To download a copy, go to metlife.com and click on the link at the bottom left. You also can order a copy by writing to MetLife Mature Market Institute, 57 Greens Farms Rd., Westport, CT 06880.

The Kaiser Family Foundation is offering "Medicare: A Primer 2010." To download a copy, go to kff.org/Medicare and click on the link in the right panel.

And you can find help at medicare .gov, where you can download a copy of its official handbook, "Medicare & You 2010." The link to the 124-page booklet is on the bottom of the page under "Resource Locator."