Welcome to Smogon! Take a moment to read the Introduction to Smogon for a run-down on everything Smogon, and make sure you take some time to read the global rules.
the games from the King Of The Beta tournament can be found in the Episode Archive of http://day9tv.blip.tv/ or at youtube.com/day9tv
for more high level/tournament/etc. games you can check out:
youtube.com/hdstarcraft
youtube.com/blizshouter
youtube.com/huskystarcraft
and many others