Reddit mentions of Aaron Mattes' Active Isolated Stretching

Those exercises are a great start. You can also search youtube for videos for exercises, this video series seems to do a good job. I would also highly suggest looking up rotator cuff stretches and exercises (second most common injury site for MT's besides the hands). You can also ask your teachers for some suggestions.

If you don't mind spending a little money, the hand workout I personally use are taken from this book by Aaron Mattes active isolated strengthening, and the exercise handout that came along with this product. Aaron Mattes also has a very thorough book on isolated stretches.

Also this is a helpful free website on self-massage if any particular muscle group starts to ache you should start massaging it routinely before the tension level increases any further.

Feel free to PM me if you need any more help on the subject.