Praise dirt and hail a recycling superhero in a lush crop of kid books for Earth Day.

Along with familiar characters like Little Critter and important ones like Nobel Peace laureate Wangari Maathai, MySpace makes its first foray into offline publishing with a branded how-to book for teens to mark the occasion.

• "Michael Recycle" (Worthwhile Publishing, $15.99, ages 3-8) by Ellie Bethel and illustrated by Alexandra Colombo.

In the whimsical town of Abberdoo-Rimey, the "garbage was left to grow rotten and grimey." Until a freckle-faced, green-caped crusader with a metal colander for a hat drops from the sky head first into a trash can. Young Michael Recycle lectures in this frenetic and richly colored picture book: "You've got to recycle! You've got to act soon! Before all your trash reaches up to the moon!" When residents learn their lesson and clean up, they throw a big party and decorate with green toilet paper, careful to roll it back up "to use again later."

• "The Dirt on Dirt" (Kids Can Press, $15.95, ages 9-12) by Paulette Bourgeois with Kathy Vanderlinden and illustrated by Martha Newbigging.

Learn how a grain of African sand can hitch a ride on hot desert air and travel thousands of miles to settle under your bed. This wide-ranging book tackles the tilt of the Leaning Tower of Pisa, the role mud plays in the creation of fossils and the mega-problem of landfills tainted by chemicals. Home project ideas include growing an edible teepee with pole beans. There are factoids galore: Charles Darwin observed, when he played classical music to his earthworms, that they ate on high notes and headed underground on low ones.

• "Planting the Trees of Kenya: The Story of Wangari Maathai" (Farrar, Straus and Giroux, $16.95, ages 5-8) by Claire A. Nivola.

Both author and illustrator, Nivola uses delicate watercolors and lyrical prose to bring alive the sacred fig trees and pure streams of Maathai's youth on a peasant farm in the fertile hills of central Kenya. Maathai, founder of the grassroots Green Belt Movement, returns home from college in America in 1966 to find gardens dry, her people malnourished and her beloved trees all but lost to commercial farming amid rapid population growth. An author's note assists parents with context: Maathai won the Nobel in 2004 in recognition of her work to replenish the trees of Kenya, where the vast majority of people depend directly on the land for survival.

• "MySpace/Our Planet: Change is Possible" (Harper Collins, $12.99, ages 14 and up) by the MySpace Community with Jeca Taudte.

Featuring eco-tips from actual MySpace users, on a subject dear to the online network's co-founder, Tom Anderson, this hip guide to saving the environment includes ways to "shop right," like buying shoes made with recycled soles and throwing a swapping party with friends. There are suggestions for eco-friendly dating (skip dinner and a movie and help clean up a park instead) and calls to action marked "Do This Right Now," such as going car free for an entire day. In the "Your Free Time" chapter, there are ways to responsibly recycle CDs during the dramatic shift from disc to download and a plea to toss your trash at concerts and music festivals.

• "It's Earth Day!" (Harper Collins, $3.99, ages 3-7) by Mercer Mayer.

Little Critter learns about Earth Day in school and is called to action by a movie on the North Pole's melting ice. He must save the polar bears and heads straight for the computer to figure out how. Not satisfied that turning off lights and using less water will be enough, the young critter comes up with an ice-cooled invention that doesn't work quite right but leads him to a revelation.

• "Eco Babies Wear Green" (Tricycle Press, $6.95, ages 1-3) by Michelle Sinclair Colman and illustrated by Nathalie Dion.

This bite-size board book features trendy tots decked out in all-natural knits. Dad's got a rubber ducky tattooed on his arm as he changes baby's green-colored diaper on the opening page. Eco babies are tree-huggers, bike passengers, Cheerio-tossing composters and know to always, always turn off the lights.