Purchasing
The best advice in the world for buying a bow is to purchase one that fits you. When you are thinking about buying a new bow, go to a proshop and check out the bows on hand. Try pulling it back, see how it feels in your hand and if it is comfortable for you. Check the draw weight, the draw length and whatever you can think of. Just make sure you are comfortable with it before purchasing the bow.

Arrows
Depending on your choice of arrows, whether they are carbon or alumiunm choose the right arrow for your bow. Every arrow manufacturer has their own arrow charts for different draw lengths and draw weights.

Broad heads
The choice between cut on impact, mechanical or the fixed blade broad heads is a tough decision to make. This is something that is personal preference. There are literally enough broad heads on the market today that naming just one is not fair. They all will do the job. Try different ones and use the one you prefer, not what someone recommends.

Outfitting your bow
The essentials are arrows, a quiver, an arrow rest, a release (for those who use them), a stabilizer, a sight with peep sight and string whiskers. Sometimes the cheapest on the market will do nicely, but for those that want top of the line. They are there also. Basically you want to keep your setup as simple as possible.

Sighting in your bow
The only advice I can give is to start out at ten yards and shoot three arrows and see what the grouping is. You may have to adjust your sights up, down, left or right depending on where you hit the target. For some it takes time and for others it may not. You want get your grouping in a three inch circle. If you can get your grouping tighter than three inches, so much the better.

Practice
Practice, Practice and Practice some more. Try to practice every possible scenario, as this will help in the field. Practice from your stand, sitting down, standing up, and shooting in an awkward position and any other way you can think of. Try using a 3-D target and placing it at different angles to you. This will help with shot placement and help with your confidence.