The look and appearance of your blog can actually have an affect on how well your blog performs with attracting new visitors and encouraging repeat visitors.  When choosing a template, it's important to think about what message you want to convey as well as what type of visitors you want to attract. 


Your blog should also be easy to navigate and pleasing to the eye.  If a blog has an unattractive color scheme, that could cause visitors to leave before they even had to chance to read any of your content.

There are several sites on the Internet that offer free templates.  Free templates is a great way to get started with a great looking design.  As you blog advances in popularity and you're able to make an income from blogging, perhaps at that time you could look into having your template professionally designed.  I already know which features I want my blog template to have and the features I don't want so I'm prepare when the day comes for me to hire a professional designer.

Here are a few sites where you can find free templates.  If you know of any others, please either email me the link or include it in the comments.  Thanks.

Blogger

BTemplates 
Blogger Templates Blog
Blogger Templates

Wordpress

Free Wordpress Themes
Wordpress Themes Base
Wordpress Templates