I give my dogs a bath about once a month...their coats are shiny and clean... I would suggest an oatmeal based shampoo that does not dry out the skin and is great for sensitive dogs that may have allergies...
I use "Sadie's Choice - Oat Shampoo for Pets"
If you bathe your dog once a month, there's no need to brush them. In fact if I brush my pit, her skin gets bumpy and she gets itchy..so I've never done it since and she's fine.
If you have a border collie or a maltese..then you might wanna get a good brush