It's not too hard. You will need a fletching jig. Bohning makes one for 30 bucks. It's all plastic and I actually like it. It's what I have at the house. At work we use Bitzenburger's and they're nice, but not work 70 bucks in my opinion. In all honesty I think the Bohning one does a better job. You'll also need some glue. Get the stuff that's kind of like super glue, like this:http://www.cabelas.com/p-0014534415222a.shtml
That's what we use when we are out of Goat Tuff. The instant bonder it comes with is nice too since you can spray it on there and when it's evaporated the glue is dry. Good for when you have a ton of arrows to do and not a ton of time. The glue will set in about a minute by itself though.
If you go pay to get them done the price will vary. At Gander we charge 2 bucks an arrow (which is dirt cheap for refletching) other places around here charge 6 bucks a piece+ because they don't like doing it. Me, I like fletching arrows. It gives me some down time and is kind of relaxing.-