Just an idea...there are some cute Peter Rabbit/Beatrix Potter fabrics online. A-B-C is a good theme for either boys or girls, as are numbers, farm animals, zoo animals, etc.
If you want to start with a panel that you can border with pinwheels, take a look at fabric.com and put "panel" in the search line. I've used some panels for soft books to make really cute quilts, cut them up and put the "pages" in order for blocks with either sashing or an alternate block. I have the "So Many Bunnies" book panel that I have not made up yet, but it is soooo cute. I'm going to make it up next time I need a baby gift. It has lots of green, blue and brown, gender neutral.
http://www.fabric.com/SearchResults2...3-26a376046a5e
Fabric.com has a lot of other cute panels (Paddington Bear, A-B-Cs, etc.) as well that are a wonderful start for a baby quilt.