TOP LEVEL DOMAIN (the .com part of your URL)

Generally choosing a generic  top level domain is a good idea. .com is the most popular but from everywhere I read using .org, .net, .info or whatever.  People generally want to get .com, and I would recommend that as my first choice, but getting another generic one is fine, just harder to sell if you ever want to flip it.

**REVISED Aug 13, 2008 – Google is now heavily penalizing .info domains due to them being spammed heavily so stay away.

If you are going to target a niche in a non-USA country using a country specific top level domain might be beneficial. for example: in Canada using a .ca URL might be beneficial (as it will rank higher at google.ca).

DOMAIN NAME (the screwyougoogle part)

This should contain your keyword string. If you want to target ranking high for  “why turtles operate quickly” then getting the url “whyturtlesoperatequickly.com” is your best option. Generally (at least for me) if you want a keyword(s) that are searched regularly all the URL’s are bought up so I’ll add on a word that makes it sound like a magazine or paper like “today” or “daily” to get “whyturtlesoperatequicklytoday.com”. Alternatively think about better targeting what tye of visitors your want, if you’re selling green widgets use “buygreenwidgets.com” instead of “greenwidgets.com”. Adding the word “online” can also be a good idea.

Basically the important thing is to realize that a lot of domains are bought up and it is hard to find one that fits you sometimes. Just keep looking and don’t get discouraged, and MAKE SURE YOUR KEYWORD STRING IS IN YOUR URL.