I'd recommend bowhunter ed for starters. If it is not required in your state, then I would recommend going to an online bowhunter ed site and at least going through the information. Now....
You might could ebay. Got both of my bows off there for around 200-250; bows can decrease in value pretty quickly even though they remain good bows. I would highly recommend having a pro shop help get you and your bow set up to each other once you have all the goodies to put on it. That will save a lot of time for you.
Now, the following is just me. There are tons of opinions and a wider array of good equipment than what I am mentioning, but the following is something to keep in mind.
You might receive a used bow with little string/cable life left in it. If so, start with new string/cable.
If the bow is naked, I'd get a 3 or 4 pin sight (a 35 dollar truglo will work), a peep, caliper/release, get it d-looped - I like whisker biscuit arrow rests and prefer my drop tine model to my original; a quiver; some vibration dampening devices such as limbsavers; I prefer to shoot with a bow sling. Arrows: the choices are vast. I prefer carbon over aluminum, and you might try some cabelas carbon hunters. They're not very expensive and will work well. Vanes: I shoot both 2" and 4" vanes and have compared them to 60 yards with no noticeable difference--then again, I shoot mechanical NAP Spitfire broadheads which fly very well. I imagine fixed blade shooters may say otherwise, but I've never shot fixed blades and have no say there. The 2" blazer vanes and similar copies have received much praise, but for what I shoot, they simply show no difference. You'll need a target, whether a combo field point / broadhead target or separate targets. When you sight in, sight in with the exact equipment you will be hunting with (as you would with a rifle).
If the season's soon, it'll take a lotta practice if this is completely new to you... Get your bow set up, research and ask questions on specifics if you're not sure what to get, have it tuned, and shoot a LOT. Be honest with yourself and your abilities and don't try to go beyond them in the field. I feel that trigger control is the most important part of shooting for both rifles and bows; keep that in mind, as well as follow-through. If you are hunting from a stand, you might pre-mark yardages so there is no guessing.
In a nutshell..
Bowhunting is a completely different experience from both centerfire rifle hunting and muzzleloading. I will warn you that it can become habit-forming and may cause daydreaming, lack of focus at work, and anxiety. Consult your physician if you have an erection lasting longer than 4 hours.