On Your Mark, Get Set, Go! by Alva Sachs, illustrated by Patricia Krebs (Three Wishes Publishing, 2009).
This is the story of a day in the life of three best friends. Marcus, Justin, and Mario start their Saturday playing videos and making lunch. When they're not sure what to do next, Justin's dad suggests enjoying the nice weather outdoors, and helps them spruce up their old skateboards. They invite the other dads to come and watch them race in the park. While it's a simple story, it's nice to see diverse friendships and father-son relationships. I really love the illustrations by the Argentinean artist.
The author and and illustrator have collaborated on several picture books. More information can be found here.
Disclaimer: I received a copy of this book from the author in exchange for an honest, unbiased review. All opinions are my own.