A good book to start with is "Winning with the Doubling Cube" by Peter Bell. It's $30 on Amazon or at
www.thegammonpress.com. The book starts with the very basics of using the cube and builds from there, so it's a great introduction for beginners and intermediates.
Like most books targeted at beginners, it gets unfairly (in my view) poor reviews from players who are fairly advanced and complain that the book "didn't teach them anything new". Of course it doesn't, because it's not aimed at that audience. But if you're trying to learn the cube from scratch, you should find it very helpful.
BTW, if you are learning the cube for the first time, DON'T read the cube problems that I wrote for this site. They'll seem difficult and confusing. Learn the basics first, and then you can tackle those problems.