Ref. Url: https://www.google.com/support/googleanalytics/bin/answer.py?answer=55541&hl=en_US

How long does it take to see report data after adding the tracking code?  

Google Analytics generally updates your reports every 24 hours. This means that it could take 24 hours for data to appear in your account after you have first installed the tracking code.

If you’ve installed the tracking code and are still not able to see data after 24 hours, please read possible reasons as to why your website isn’t being tracked.