Hi Donna,
I have three Bichons and it can be quite a task when they are matted. The pros use a special tool that combs and cuts the mats at the same time with sharp blades called a dematting comb
see: http://www.progroom.com/catalog/index.php?cPath=170_171&sort=1a&page=2

Sometimes I just pull the mats out a little at a time but I typically have them groomed every 6 weeks and keep their coats a little shorter than the AKC standard.

Once upon a time I had 4 but we lost Angel 2 years ago to colorectal cancer (at 16). Peaches, my first Bichon is over 17 and failing very fast. I have 2 boys, Edwin and Max Jr., from the same litter, who were a gift from Angel. I wouldn't have survived my cancer adventure without them (well ok, I guess that my wife helped a little ;-) Some of my puppies (I was a breeder for a while) have done the "paw dance" but not these two. They're more into being Velcro dogs. They are the perfect companion dog (except for the constant grooming thing)