Aim to keep most of your milk in the fridge unless you don't plan on using it within a week. Some women's babies don't accept any frozen breastmilk. If your baby objects, try scalding the milk before freezing. Although this will, of course, get rid of the immunological properties of your milk, it will still be better nutritionally than formula. Experts disagree on the best freezer storage technique, plastic or glass.
Plastic storage loses some of the fats, and glass storage loses some of the leukocytes.
Use whatever storage works best for your own situation. Remember that the amount of milk you pump is unrelated to your milk supply. Some women easily pump 10 ounces a session. Others can barely pump an ounce in 20 minutes. Expect your baby to nurse a bit longer and more frequently at night.