This pattern might make a starting point for you. I've used it for dish cloths and made a large triangle shawl my DD uses from it. It makes great baby blankets. You could make a small piece to get the hang of working with the increases for a triangle and go from there. There are also tons of shawl patterns available, some of them increase in the center.
http://www.ravelry.com/patterns/libr...thers-favorite