Dear Ms. Lundin,
Four excellent texts, which include your texts for school, are A Beginner's Guide to Transfiguration, Intermediate Transfiguration, and A Guide to Advanced Transfiguration (texts for first through third year, fifth year, and NEWT-level Transfiguration at Hogwarts) and Theories of Transubstantial Transfiguration, which is required reading for those who wish to pursue their Mastery in the subject. I also recommend the monthly Transfiguration Today, available in the periodical section of the Library.
I remind you that the use of magic outside of school is strictly forbidden to the underage witch or wizard, and encourage you to practice under the supervision of those who have, at least, achieved Exceeds Expectation on their OWLs.
If you indeed are possessed of a singular talent in the subject, please see me for career possibilities where your skill will be used to your best advantage.
Hogwarts School of Witchcraft and Wizardry