There many different opinions on this, but when designing a web page, what is the best window size, or viewport size that you should cater for? Now this is assuming you want to cater for the broad general public (meaning should you create a gaming website the people rolling there won't have 800x600 screens...)
Also, is it best to leave the main containing div at an auto size (so that it stretches with the screen size, assuming you do not have any fixed elements inside that you do not want stretching) or do you fix your width? I've designed a few websites, but I'm still not sure what is best practice in 2012.