ok nevermind, i answered my own question:
K&N has a "Million Mile Warranty" or basically for the life of your vehicle. K&N says their filter will go up to 40,000 or more miles before needing cleaning. K&N also says that you should not clean your filter more than 25 times or the cotton filter media can become to worn to filter effectively.
also!! i have answers for u alex

here is the site for cleaning your filter: http://www.knfilters.com/clningins.htm
and here is some information that should interested those who want to read about the K&N filters: http://www.dccarcare.com/tipowk/tipowk20.html
hope they helped!