Any time you are trying to launch a site on a new platform, there are tons of things and details to keep track of. Thankfully, the folks at SaleAMP have a great website migration checklist (PDF) to help you keep track of everything. I found it thanks to Smileycat Blog.
There are plenty of these out on the net, and the best checklist is one you’ve made by yourself by going through the process multiple times. But, this is a great place to start until you’ve got your own list made up.