I’m not an expert on this, but choosing a domain name for your web site is a deceptively important subject and I’ll share some of my thoughts with you:

• Shorter is better, but longer names aren’t strictly off limits. HowToIncorporateInKansas.com (not a real domain) is long, but not hard to remember.
  
• Use your name, if it’s available. It’s often easier to remember a person’s name than a descriptive name.
  
• Also use a descriptive name for marketing purposes. If you’re looking for an estate planning attorney in San Antonio, you might click on SanAntonioEstatePlanning.com whereas you probably wouldn’t click on JohnJones.com without some descriptive text next to it. You can use both URLs; point one name at the other.
  
• Do whatever you can to get the.com version. If it’s not available, try another name. Use your initial, put the word “law” in it, or your state or city. For competitive purposes, you might also want to buy the other common variations (net, org, biz, info).
  
• Avoid hyphens, abbreviations (your city or state might be okay), and numbers (i.e., “4” for “for”).
  
• Choose a name that people can remember and spell. You will be giving out the name on the telephone, from the podium, etc.
  
• If your web site is hosted at http://yourname.typepad.com, get your own domain and point it. Better yet, get your own hosting.
  
• If you intend to advertise (offline, Adwords, etc.) you will want lots of descriptive domain names. You can set up separate lead capture pages, or point each name at different pages on your main web site. Get names for each practice area, each target market, at least.
  
• Use key words in your domain names.
  
• If people commonly misspell those words, consider buying the common misspellings, too.
  

You can buy domain names for under $10/year. I buy mine at http://homepagedomains.com

For more on what makes a good (and bad) domain name, and a lot of fun, check out http://goodurlbadurl.com/