http://www.pyzam.com/bloggertemplates

Here is a link to a site that has tons of blog layouts for Blogger.com! Once you have found a layout you like, copy the code for the layout & go back to Blogger so you can edit your layout!
To edit your layout go to your "Dashboard", then click "Layout". This will take you to a new page with some tabs near the top - you need to click "Edit HTML". On this page you can go to the bottom where you should see a text box that says "Edit template" & has a bunch of codes on there that won't make any sense to you.
Select the code in the text box & delete it, then paste the code from the layout you found!
Don't forget to save!!