The domain name is one of the most important decisions that you can make when starting a website. There are a few things to consider when you're picking a good domain name.

1. Keep It Short
You want people to remember your domain name, so try to keep it as short as possible. 10-15 characters is best for this.

2. Make It Memorable
Don't compromise on being memorable to make the name short. It's better to have something catchy than short. One of my websites has a 25-character name, but it's turned into an abbreviation among the userbase on the site, and everyone remembers it very well.

3. Hyphenate If Necessary
Have a great idea, but someone else had it and already registered the name? No matter, put hyphens between the words. There's some debate as to hyphenated names, but in my experience it doesn't hurt.

4. Avoid Non-Dot-Com TLDs
.info and the like are generally associated with lower quality sites. Also, people are more likely to remember a site whose URL ends in .com instead of anything else. If the .com version of the name you want is taken, try .net (only if it's a really good idea) or just come up with another idea.

Remember that the domain name can make or break your site, especially if you plan on using viral marketing or anything of the like to promote your site. The more your URL stands out, the more people are going to remember it, and this ultimately means more visitors for you!