For a long time I had been wanting to change the Plate Diaries blog from two to three columns. The layout and organization is a mess and it's a hard blog to read. I finally sat down one day and poked around the internet, looking for a template to try. If you want to look around, your Google search terms for this could be:
blogger template three column
If you are interested in changing your blog template, first copy and paste all the HTML from your existing blog into Notepad (it's a no-frills word processing program on your PC.) Do not use Word because it will change the format and mess up your HTML. Save the document.
Next, open each widget you have on your blog sidebar and copy the HTML into another Notepad document. These may go bye-bye when you change your template and I know you don't want to risk losing all that stuff. Save this document, too.
Third step, while strongly suggested, is not required: start a new blog. Keep it private and out of the search engines, and use it just to mess around with the code and experiment. I've had one for months and every now and then I test something there before putting it on a public blog. This has been a lifesaver for me.
Next, find a template you want to use. I tried several beautiful templates from various "free blogger templates" blogs and got Blogger errors with each one I tried. Giving up on that, I reverted the test blog's template back to Blogger's Minima Stretch, then implemented the code found at this site:
The easiest way to find the locations mentioned in this tutorial are:
1. Open the above link in a new tab or window.
2. Open your blog's HTML page in a new tab or window.
3. Go back to the site with the code you will copy and hit Ctrl+F to open a search dialog box. Type in a little of the code you are to look for when inserting some new code.
4. Navigate back to your blog's HTML and search.
After spending all morning dinking around, looking for a template that works, and is the right width, there is only one thing I can say: