Many books will tell you that a Westie should only be bathed once or twice a year. Bare in mind that most of the information in these books are from people that show their dogs.  Most of these dogs are not allowed to go outside and play with other dogs or get dirty like a normal dog. Most of them are kept indoors and in runs with  cement floors. The average pet Westie does go outside and gets to play with other dogs and YES they get dirty. So they need to be bathed more often. When a Westie does get wet and dirty often once they are dry a good brushing will do the trick. If you feel that they still don't look good then feel free to give them a bath with a good quality shampoo. Don't ever give your Westie a bath if they are matted a bath DOES NOT get rid of mats it only makes them worse. Make sure your dog is free of mats (tangles) before bathing. On average I give my dogs a bath once a month. Yes bathing does soften the coat but unless you are showing your dog who cares. It just makes them nicer to cuddle with. Westies were bred for digging so their nails grow very fast. I cut my dogs nails once a week. Most Groomers will be happy to show you the proper way to cut nails. You can keep your Westie in a natural coat (not clipped), have them hand stripped (only necessary if showing) or the pet clip (cutting the hair rather than hand stripping) All my dogs are in a variety of pet clips. Which ever style you choose, your Westie should be brushed and combed out at least 3 times a week. This will keep your dog from getting matted and prevent loose hair from ending up on the furniture. There is nothing appealing about a neglected Westie. Here are two examples of neglected Westies. One was taken away from a (back yard breeder) by the SPCA and I groomed her and fostered her until she found a permanent home. And the other the owner said she read in a book that a Westie should only be groomed once a year.