Hi I was wondering what audio files people use and where you get them from  on a Tardis that is activated once doors open and shut thank you 

http://tardisbuilders.com/index.php?topic=6603.0

That depends on whether you want Classic or New-who door sounds.

The classic era had the more electronic sounding doors, whereas the new series (due to not having separate inner doors) has a more wooden creaking sound. (The 1996 movie combines the two effects)

For the newer sounds I'd suggest the youtube channel: https://www.youtube.com/user/TARDISSFX which has all the sounds you could possibly want. There are plug-ins and websites that can download the audio of a youtube video.

For the Classic era, I haven't yet found a source that's as comprehensive, or well catalogued, as the TardisSFX channel, people usually just upload things called 'doors' or 'tardis takeoff' without any indication which version/era/episode it's taken from. So your best bet is the link in the thread elkad pointed you to.