Depending on the diaper system(s) that you choose, you will also need a variety of cloth diapering accessories.
Diaper Pins - The classic safety pin which is used to fasten diapers together. The best type to use for diapers will be labeled for use on diapers, and will feature a locking head, which will prevent a baby from accidentally opening the pin.
Snappi - A snappi is an alternative to metal pins for those that don't want to or know how to use pins or for those who might be scared to use pins with a baby. They are made of a stretchable, flexible plastic, and are t-shaped, with little combs at each end that grip into the diaper fabric.
Wetbags and Pail Liners - Wetbags are a waterproof, odorproof bags, usually made from PUL that are used to store soiled diapers when you are out and about. The bags come in a variety of prints and sizes. The size you need will be determined by how long you will be out, and by how many diapers you go through during that period of time. Most wetbags hold anywhere from 2-8 diapers. They are usually held shut by a drawstring, zipper, or velcro. It is always a good idea to have two wetbags, one to use in the diaper bag, and one to have in the wash. Pail liners are similar to a wetbag, only they are designed to be used inside of a trash can or other diaper pail. Some people opt to use a large wetbag in lieu of a diaper pail. A large wetbag will usually hang from a hook or doorknob.
Inserts - Inserts typically refer to the absorbent pads that are used in pocket diapers. They are usually made from several layers of cotton, hemp, bamboo, microfiber, or a combination of materials. The amount
Doublers - Doublers are pads used to increase a diapers absorbency. They can be added to a pocket diaper along with the insert, or they can lay on top of of the diaper. They are also available in a variety of materials (microfiber, cotton, etc).
Liners - Liners are placed next to the baby's skin and are non-absorbent. They can be used to wick moisture away from the baby's skin so that the baby feels dry (typically a fleece liner), or they are used to protect a diaper from stains and diaper rash cream. They can also be used to help make diaper clean up easier. They can either be disposable or reusable.