Ditto to the other posts.
If you can't take lessons, get yourself some REAL dvd's or books from well-known and trusted barrel racing names such as Martha Josey, Charmayne James, Sherry Cervi, etc. Yes, they might be $$$ but you want to start your barrel horse RIGHT. And often, you just can't trust YouTube videos for stuff like that, especially if you don't know what you are doing either. (You wouldn't know what is right or wrong.)
You don't have to have a barrel racing saddle (you could barrel race bareback if you wanted) but think of it this way: A professional basketball player wears basketball shoes and a jersey. A professional football player wears pads, a helmet, cleet shoes, and uniform. While you don't *have* to have basketball shoes to play basketball (you can run in flip flops, right?) and you don't *have* to have pads to play football .... if you are serious about what you are doing, you are going to want the proper equipment to do it.
So you don't need a barrel saddle to start out with, but you may want to consider getting one down the road if this is something you seriously want to do. For a slightly more cheaper option, you can buy a used name brand barrel saddle. It will be a bit cheaper than buying it new, however, a good quality saddle will hold its value pretty well. Streakin has got a pretty good list of saddles there; go by that.
The best advice I can give you for starting your horse on barrels is to get the horse 100% broke before you do ANY barrel training. The horse should be able to walk, trot, and gallop with control and at any speed you set. They should also be able to back up, stop nicely, direct and neck rein, and respond to leg pressure (so you can side pass and also ask for lead changes). Basically, you should be able to move your horse's body in anyway with no problem.
Also, when you do start working on the pattern, TAKE IT SLOW. The easiest way to sour or ruin a good prospect is pushing them on the pattern too fast too soon. And bad habits are harder to break, than just creating good ones in the first place. In the early stages, you can do the pattern over and over in one day (with reason; maybe no more than 10 times .... depends on the horse) but remember that there are lots of things you can do to practice the elements of barrel racing without actually using a barrel. This is where getting the horse sensitive to your legs, getting good at turning, doing rollbacks, neck reining, lead changes, etc etc etc all come into play.
∞•*˚ Βгįťţαňγ ˚*•∞
It is not enough to know how to ride; one must know how to fall.