If you are a frequent user of your camera, you will need to worry about the storage issues. A good memory card may help you solve that issue, and here are some points to note when you are choosing one.
Types: There are usually 3 types for you to choose from: Digital card, Eye-fi card and CF card
Storage: Ok, the most obvious one. Usually the decision will be between 32GB or 64GB
Speed: This is an area where many people forget. You will want the photos to be uploaded fast, not after several days