Our favorite knit-it-up-quick baby blanket is Sonny's Blanket, designed for us by Caitlin Geronimo. It is designed for and kitted up with Blue Sky Fibers' Organic Cotton Worsted, 100% cotton yarn. 
The kit includes 5 colors of yarn and the pattern.  
Difficulty: great for a beginner. Knit flat on circular US 9's. A circular needle is used to hold the large number of stitches. 
Finished size: approximtely 32" x 36"
Color choices:
1 (sample): Lemonade, Dandelion, Poppy, Pumpkin, Tomato
2 (pinks): Tulip, Shell, Parfait, Lotus, Raspberry
3 (blues): Bone, Periwinkle, Caribbean, Mediterranean, Jasper
4 (tranquil): Drift, Sleet, Orchid, Thistle, Jasper
5 (brights): Lemongrass, Lotus, Poppy, Caribbean, Orchid