A lot depends on what they are mixed with. In general, a dog with longer hair should be professionally groomed every 4-6 weeks, and brushed at home every day. As puppies, I would recommend you take them in for professional grooming around every 3 weeks, as their hair will be changing, and this will help them become comfortable with the grooming process. Usually dogs are bathed as part of the grooming process, so you should not have to do this at home.