Where do I start?

Have you thought about tape recording your readings? Perhaps one of those microcassette recorders that is voice-activated, so you can focus on your cards & then go over to type out your notes at the PC . . . .
It would also let you "hear" how you would sound to a sitter. Just don't be too hard on yourself at the beginning!

A couple of books that I'd recommend are Mary Greer's 21 Ways to Read a Tarot Card and The Complete Tarot Reader by Teresa Michelson. They both guide you through working with whatever deck you choose.

Patricia