Check this site

http://www.bloggerthemes.net/ is an incredible site!

Why? well if you answer YES to any of the next questions is just because blogger needs more themes and this could be the answer:

-Bored bout the default themes on blogger?
-You dont know how to use another theme?
-You want something awesome (graphically) and blogger doesnt have the answer?
-You dont want to use another platform?

Dont worry this site is incredible and has a lot of themes!

But this is free? I will have to pay? If this is free, the themes worth the time to look for them and upload to blogger?

Yes, yes and yes. Ive been looking for all the site, and I dont found any pay-for theme, and as far as I know the site owners wont ask for money in the future, there are some themes that obviously are bad looking, but are just a few, and if you are new or dont know how to put another theme in blogger is simple as follow the next steps:

-Go to http://www.bloggerthemes.net/
-Look for the theme that you like (remember that for alomost any theme you can change the background, some colors and the style of the blog, so there are a lot of customization options)
-Download the zip file
-Go to the managing site for your blog
-Go to the Design tab
-Go to HTML Edition
-And select upload a theme

Now your blog is going to look even better!