Ya, You should know the basics before owning a horse. Not knowing how to brush is NOT a good sign... I really don't think you should be owning a horse if you don't even know how to brush one...
But, I will give you some information for ur horses health:
1. Start with the Rubber Curry. The rubber curry should be used in a circular motion to loosen dirt that has settled under the horse's hair. NOTE: be very careful and gentle around bony areas of your horse's body (such as his back or shoulders). Don't use a Rubber Curry on your horse's legs unless you can be extremely gentle with it. Never use a Curry or any stiff brush on your horse's face. It's too easy for your horse to injure his eye on the rubber curry or stiff bristled brush, and eye injuries are usually serious, needing immediate veterinarian attention.
2. Next, use the Dandy Brush. The motion for this brush is like the same motion you would use when sweeping a floor. You 'flick' the brush away and up from the coat so that the dirt comes off of his coat. Unless your horse is already extremely clean, you should see a slight cloud of dust with each stroke. If you don't, you need more "flicking" action with this brush. If you don't use this "flicking" motion, the dirt will just get pushed back under the hair, potentially causing irritation to the horse.
3. Then, you use the Body Brush. The body brush is meant to smooth down the hair and to get rid of any traces of left-over dirt after you have thoroughly used the Dandy Brush. With the Body Brush, you do not use a 'flicking' motion, instead, you smooth it flat over the horse's coat to flatten the hair. This brush often gives the horse a shiny, clean appearance (but only when the brushes are used in this order!)
4. Next, use the Mane Comb to gently comb the horse's mane. Use the Dandy Brush to brush the horse's tail. Many people use the comb to brush their horse's tails, but I don't use a comb since it breaks the hairs more easily. If you want the horse to grow a long, flowing tail, you should use the Dandy brush instead (or don't brush the tail at all...in this case, you could use warm water to rinse the tail, then apply a tail conditioner or Show Sheen to keep the tail from tangling or getting knots).
5. Now, on to the feet! You should first have your instructor show you how to pick up a horse's feet. Usually, this can be done by running your hand down your horse's leg, then gently squeezing his fetlock (ankle). Be sure not to pick up the horse's foot too high, or he might loose balance. When you use the hoof pick, always scrape away from you, just as you would if you were using a carrot peeler. You don't want to accidently injure yourself or your horse if he suddenly moves or pulls his foot away. It is important to thoroughly clean out the hollow areas on both sides of the frog, and around the sole of the foot. For an illustration of these areas of the hoof, view our Parts of the Hoof & Foot article.
6. The last step is using the Towel. A plain towel or rag will do, just wipe it over the horse's coat to bring out the shine.
TA DA! You're all done!
When you are finished riding, it is good to give the horse another grooming to remove any sweat marks or dirt that accumulated from the arena or trail. It is also a wonderful 'after riding' reward for horses who like to be groomed
There are many horse sited to look for more info....
Equusite.com (where I got this) Horse grooming - Wikipedia, the free encyclopedia
And many others.. just look it up on google...
But this really worries me, if you own a horse, but don't even know how to brush one O.o
Maybe you should reconsider owning a horse until you learn the basics