Welcome to YT!!
Well you can find all kinds of information here on YT on all those subjects. Just educate yourself - and read, read, read the threads here.
I wouldn't start buying clothes until I had my puppy all picked out -- because it is really hard to know what size to buy. We have some fabulous vendors here on YT and many of them will custom make clothes for your yorkies measurements - and at a reasonable price
As far as grooming products - I would recommend Buddy Splash -- for all the tangles & to freshen your pup. Buddy Wash & the conditioner. These are all Cloud Star products and may be available in a store or from a vet near you. Here is the company website
www.cloudstar.com
You need a good pin brush. I love the Chris Christensen 20mm gold pin brush
Pin Brushes
Best wishes & if you haven't picked out your puppy or breeder & put down a deposit -- read this now!!!
http://www.yorkietalk.com/forums/yor...ead-first.html