where i can find ccna documents or papers to prepare for exam free?

The first source link is to a list of free practice tests for the CCNA available online. This list is provided by About.com. I have used their website before for A+ certification information with success.

The second link is to an article that tells you all about the new exam. I thought it may have some good information to help you start preparing for your test.

After looking at the article, you should make a list of areas that you feel that you need to prepare. Then, search out the specific information you are looking for and prepare for each section. Be sure to take as many practice tests as possible!

Best of luck