You're ready for it?
Have you ever had a long haired dog before?
Bring your dog to the local PetCo and start trying out different COMBS - brushes won't do anything. You might want a rake. You want teeth on the comb or rake that are WIDELY spaced, 1/4 inch apart is ideal - this will pull out the undercoat.
I bring my dogs inside to comb them out because it produces so much hair. Just do it in a room that's easy to vaccuum. If your dog has never been groomed before, be patient. I'd recommend you start right now. When your dog is sick of grooming (which will be quickly if she's never been groomed before) quit, and then start up later again.
It takes me about 1-2 hours to completely comb out my dogs, and I'm good at it. I have Samoyeds though and I'm pretty obsessive about their appearance.