Tuffy's hair is pretty long right now so I try to brush it every couple of days.. usually 2-3 times a week, I'm kinda lazy about that. He hates being brushed so I usually at least try to get his legs brushed since that seems to be where he matts the most.
when sprite and ellie had long hair---and since they would play and bite each others hair, i found it necessary to brush their hair at least 2 times a day. and every time i would brush, i would find a little knot that i had to brush out. i think they enjoy having the short hair now.
When I first give Tiki his puppy cut I only need to brush him once a week. As his hair grows in I will notice it starting to get little mats under his arms and behind his ears, as soon as I see this I start to brush him every day or every other day. In this Texas heat I will be giving him a hair cut more often therefore less brushing. In the winter when it is cooler and I let it grow out I will brush every night.
Morgan is brushed everyday, he has a fairly long coat. I kinda get this assembly line thign going as I have three dogs, and just start with the smallest and work my way through em all lol
My large dog Buddy, has a very short coat, but he is still brushed simply because it keeps him used to it, he sheds his coats and it also helps promote the oils they have in their skin to keep them from getting "dandruff".
Pico is in a puppy cut and I don't brush him everyday. Maybe I'll run a steel-toothed comb through him every couple days just to see if he's matted anywhere. Usually not. If he's 5 or 6 weeks past a haircut,though, he will start to mat more often. This is enough to convince me I don't want to let his coat grow out.
I do this in the evening while watching TV and he is laying on my lap. If I take too long, though, he'll leave me and go into the living room to lay in my husband's lap.