Melissa, welcome to Leatherworker.net. ^_^ Here are some possible answers to your questions (and I'm sure others will chime in with more help):
1. I don't know of a good book on dyeing leather, but I know Tandy carries lots of books on different subjects. I learned what worked for me by trial and error. I purchased some dye, some stain, and an All-In-One product and played with it until I liked what I saw.
2. I've heard that some folks use felt on the inside of collars, but I suppose you could use just about any soft material like deerskin suede, etc. Gluing it in should work as long as you're using a contact cement or white glue like Leather Weld.
3. Leather Balm w/ Atom Wax is a good finish. I also like Satin Shene, which is a flexible and durable acrylic finish.
As a beginner, you owe it to yourself to try out a whole bunch of different products, because each leatherworker has his or her own preferences and has discovered products that work best under their individual circumstances. I personally dye using Eco-Flo Leather Dye, condition with Neatsfoot Oil, and finish with Satin Shene, but there are many other combinations that'll work just as well!
Good luck, and let us know if you have follow-up questions!
Alex