If you are considering using a compound bow or if you already own one then I am sure that the thought has passed your mind about using an #archery bow release. Some people may tell you that they are not necessary, but there is a good chance that you can increase your comfort, consistently, and reliability with a bow release. If you look at many of the archers that shoot frequently, you will notice that they shoot with some sort of aid. Using the different type of aids available on your compound bow will allow you to keep your string nice and steady and will help wonders with your accuracy.
There are many types of releases that are on the market, but the most common for archery bows is the index finger release that is typically accompanied with a wrist strap. You can use any finger to shoot the different archery bow releases that are on the market today. You want to get one that you are comfortable with because not all of them attach to your wrist. Some of them, like the thumb or pinky shooters are free standing and are mostly favored by target shooters because of their lightning quick release. Test a few out to make sure that you are comfortable shooting, before you commit to the purchase.
As with anything in this sport, you are going to get what you pay for when you are looking at release aids. It is recommended that you get one that can be adjusted for both the length and trigger pull. The reasoning for this is that you want to be able to adjust the release so that you can shoot the bow with the joint that is below the second knuckle on your finger. If you adjust the trigger to the heaviest tension then you can increase your accuracy as well. Having a heavier trigger allows the shooter to have more of a "surprise shot."
If you are beginner, then I would recommend that you choose a wrist release aid to shoot your compound bow. You should make sure to get one that has a strap that can be tightened and set to the same position every time. If it is flimsy then it will cause your anchor point to be different every time and that will cause your accuracy to go down. This is counterintuitive for what we want. Velcro straps will be the easiest to achieve this continuity, but if you are hunting they are not the best option because the velcro will make noise. It is for this reason that I would make a recommendation that hunters should get a buckle strap.
Whatever it is that you end up with, you should make sure that you get something that is the most suited to your needs. The purpose of getting an archery bow release is so that you can improve your shooting performance, not hinder it.