Hi Tamara. When I prepared for the CAE, I found this link very useful: http://www.cambridgeenglish.org/exams/advanced/how-to-prepare/ If you scroll down the page you will find 4 links. They point to free samples of test simulations. You can try them for free as many times you want and get an automatic correction.

Hola Tamara: Cambridge University Press has a very good textbook, Complete CAE. It is excellent in showing exactly what is need for the exam and has an example exam to help you practise. But I think it's quite expensive. www.examenglish.com I think has example exam questions to practice, too. Saludos: Simón.

Any of the Cambridge University Press books will help you prepare. By the way, a good start would be to make sure you know the correct name of the exam you're hoping to take. It is called the Cambridge Certificate in Advanced English.