Choosing a Domain Name
In choosing a domain name for your website, not only will you want to think of something catchy and memorable, but you also want to choose something that includes as many of your keywords as possible.
Whenever I am considering a new website, I think FIRST what keywords I would use if I were searching for information I want to include in that website. Once I have decided on the main keywords, I then start trying to come up with a domain name that includes two or three of the most important keywords.
Sometimes I will think of an awesome domain name waaayyy before I'm ready to begin work on the website. GO AHEAD AND PURCHASE THE DOMAIN NAME! Domain names are cheap... usually around $12.00 a year. It is worth the money to go ahead and secure an awesome domain name before it is purchased by someone else.
I usually try to get the dot com, but if it is unavailable, in my experience it doesn't seem to affect the Google search at all if you wind up with the dot net, the dot biz, or another dot something as long as you know how to optimize your website. Choosing a keyword rich domain name is part of that optimization.