Another pinner said Crochet Baby Mittens - Tutorial. These little mittens are so cute and easy to make. The only change I would make to the pattern is to add some elastic to the wrist area so the mittens don't slip off the baby hands.
Baby Mittens - free crochet pattern - Made these for my youngest daughter, they are a simple beginner pattern, came out great and fit my 18 month old perfect. I made them with worsted weight yarn and an H hook.
Wonderful DIY Crochet Kids Mitten with Free Pattern