Hi! First, I have to say it is always nice to see someone being thoughtful about bringing a dog into their lives BEFORE they go out and just get a cute pup.
To answer some of your questions, lifestyles vary and it would best to find a dog with the kind of temperment that wouldn't mind being alone for some stretches of certain days. Plenty of people on here make those situations work for them. The first pup in a litter that runs to great you is NOT this pup, generally...so don't go for the old..."the pup picked me" thing, that is generally the just alpha pup and they are busy little extroverts.
Find a breeder that will interview you thoroughly and doesn't mind answering a kajillion questions, and has a solid guarantee on health (1 yr is usual). A good yorkie breeder will not release pups before 10 weeks, with 12 being optimal.
For info on care, home prep and training(the chewing thing), you can check my site at
www.sylvanyorkies.com
good luck in your decision.