The major do(s) and don't(s) to ensure a smooth launch.  Any tips ranging from A to Z would be very helpful.  I hope this question isn't too broad, but I'm pretty sure that this community has had its fair share of experiences.
Site launch do(s) and don't(s)
ecommerce;launch
Not quite a do/don't list, but take a look at Launchlist - it's a checklist of important items worth taking care of.