1) Topic: What is the website about? Define it in a few words, including audience.
2) Keywords: What will be the keywords that would describe your site best, make a cloud of them.
3) Name and domain: get the best possible ever, based on keywords.
4) Hosting: setup hosting account.
5) Local development bed. Setup the testing site or local copy where you will do development.
6) Template: either wordpress or basic “coming soon” page with chosen technologies. Do this along with 5.
7) Tracking: install Google Analytics from the start
Note: if you will be using WordPress from the get go, take a look at this post: http://onsubject.com/knowledge/?p=657