Free hat pattern on ravelry http://www.ravelry.com/patterns/library/lace-newsboy-cap-for-american-girl-gotz-dolls
Quick & Easy Crochet Patterns for 18" American Girl Dolls by Fuzzy Bundle
Finding Pins and Needles: Sleeve Sweater Dress Tutorial: for your AG doll Great tutorial that could be the basis for any AG pattern you'd like to create.
Cowboy Tree ornament
Crocheted Hat for my Cat
Hand knit sweater outfit