E.B.
My husband has been taking our 9 month old german shepard puppy to classes at K 9 University on NW Expressway and County Line. They are very good there - it is all about praise and not punishment. We will soon be enrolling our newest family member, Mollie the 9 week old Mastiff (we found her dumped in the country) for classes there as well. She is the sweetest thing - I don't know how somebody could do that.
Training involves a lot of your time as well. Every evening my husband spends about 15 to 20 minutes working with Thor. He is responding to hand signals for sit and down very well. Conistancy is very important - just like with kids all over again....
Good Luck