What textbook(s) should I read to learn Adobe Illustrator from start to mastering, and use it as a reference?
I learned a lot from the Classroom In A Book series mentioned in the other answer, and I recommend them highly, but it can only teach you so much.
If you have access to any Adobe User Group meetings (for example there is an InDesign User's Group that meets in my area), you will learn much more from experts.
Additionally, there are some amazing tutorial videos in Illustrator by Deke McClelland available on Lynda.com that will add to your expertise when you are ready for them (they are "master classes" and you need some familiarity with the software to take full advantage of these tutorials). (Lynda.com also has videos for all levels of expertise)
Adobe also has some excellent training videos that are free.
To actual learn and master Illustrator you have to use it.
If you do like to have a book as a reference you can order it on amazon right here.
In this book you find everything you need to know about Illustrator (CC).
It also contains 15 lessons that cover the basics inc. tips and techniques to be more productive with the program.
Purchasing this book gives you access to the downloadable lesson files you need to work through the projects in the book, and to electronic book updates covering new features that Adobe releases for Creative Cloud customers