If you're playing French bow, you should check out Francois Rabbath (
www.francoisrabbath.com), he has a great video out now called "The Art of the Bow" (
www.artofthebow.com).
Some people dig his ideas, others are opposed...but if you go in with an open mind and try to learn something you'll do great. Take it with a grain of salt--not all of his ideas may be right for you.
As for your bow hand, your thumb needs to not be straight at the first knuckle, but bent. It should be touching the frog where the stick meets it. I use a latex rubber grip for added comfort--Lemur Music sells them for $4 a pair. If you get that you'll want to trim it so that your index finger is not on the rubber.
Your index finger should be extended out and curled around the stick near the leather grip (some bows have a siver wrapping--whichever yours has). Your pinky should be on the frog touching rougly where the dot inlay is. Your middle finger should be touching the silver ring near the hair, but not touching the hair. The ring finger in between the pinky and middle on the frog. You should be curling your fingers so that the bow won't fall if you let go of a little pressure. Don't be holding it so that your fingers are facing down, more like at you as though you are scooping in sand at the beach or something--sorry, it's hard to describe in words. Your index finger is your power finger....and make sure to grip with the pinky too. The middle finger grips the least, and the ring is close in grip to the pinky. Don't squeeze, try to relax and use the weight of your arm to keep it on the string.
For more good info, please check out George Vance's site,
www.slavapub.net.
Good luck!!!