Familiarize yourself with different kinds of belay devices and locking carabiners either at a well-stocked store or online before you buy.
Step2
Buy a belay that also works for rappelling.
Step3
Compare the diameter of your rope to the belay device to be sure they are the same size.
Step4
Buy two or three locking carabiners: one big pear-shaped locker for use in tandem with your belay device, and two smaller D-shaped lockers for tying in at anchors and setting up top ropes.
Tips & Warnings
Avoid buying a Gri-Gri belay device to begin with. Although Gri-Gris have some big advantages, such as not needing as much attention as other devices, you'll learn bad habits if you begin with one of these. They also don't double as rappel devices.
Avoid steel carabiners or steel belay devices, as they are too heavy. Buy aluminum instead.
Rock climbing is an inherently dangerous activity that can result in serious injury or death. We recommend that you seek proper training and equipment before attempting this activity.