Logos are a very important part of your web presence. You could try to create one yourself using a graphic program and that might be fine for a personal website. For a commercial website, you will probably want to have a logo created professionally. A logo is a very important part of your business and not something to scrimp on.
You could go with a local graphic design business or try an online freelancer website.
Another option is to use a site like AAA Logo. This website works like a template and assist in creating a logo. Not a bad idea starting out but nothing will beat have a true professional create your logo.