Click on book image for more information
Spaceships, Aliens, and Robots You Can Draw (Ready, Set, Draw! by Nicole Brecke (2010)
How to Draw and Save Your Planet from Alien Invasion! by Sheldon Cohen (2011)
"This humorous guide uses a cartoonish style and clever captions to show kids how to draw and defend Earth from intergalactic invaders."
1-2-3 Draw Cartoon Aliens and Space Stuff by Steve Barr (2003)
One of a series of books. See his website for sample pages.
How to Make Comic Strips
Brian Zaikowski, creator of Demented Denizens comics, has a training video set you can download: How to Draw Ancient Space Aliens. He also has lots of alien cartoons you can enjoy on his website. Click here to visit his website.