Go to your archery range and ask some of the members who are shooting broadheads some questions. You will find that most guys will let you screw on a broadhead and shoot it, this way you can try before you buy. Find out how good your bow is tuned by shooting a fixed blade, if it doesn't fly well then you either need to tune your bow or consider shooting mechanicals as they will fly like field points.

There are several mechanical broadheads that are constantly brought up on these formus, I shot some of them and didn't care for the penetration. However, know that a well placed shot with any broadhead out there today will put a deer down (mechanical or fixed blade). Buy what works for you and your setup and what you can afford and then practice, practice, practice.