What kind of learning disabilities? Really they shouldn't get in the way unless he has difficulties reading and even then slow and steady with moms help should be golden. Patterns for kids I always like to recommend Yellow Brick Road. It's a super simple first quilt were he won't have to worry about matching corners and points. Before jumping into the quilt I have my kids make a few small things to get feel of what they are doing. Mug rugs, needle books, tote bags, a pillow case and wall hangings are my first semester then the quilt is second.
Good Luck with your 4H projects I hope you have fun with it. :-)
T