First you want to choose the template that you like.   A collection of websites with free and paid template designs can be found Here.  As an example I chose the Dribble Clean & Responsive template by Themexposed.

If you use a mac, try to find a template where the file that you download is a .zip file.  It makes life so much easier.

Once you have downloaded the template go to "Template" on the blogger side bar.  Click "Back up/Restore" on the top right corner.  If you have previous work on your blog, back up your blog just in case.  Then click "Choose file" under upload at template from file on your hardrive.

Unfortunetaly, if you have already tried to download a template.  The html/layout may be so "messed" up that it's better to just create a new blog and start immediately with a new blog template.  Just keep your old blog and you can transfer your posts.

This is what it looks like now.  You may need to play around with the layout. Delete certain things that you do not need.  For example, with this template, the about me google + widget was messing everything up. So I had to remove it.

Now for the fun part.

Open the folder with the template and look through the different folders - plugins, how to's... The txt folders will give you more information as to how to edit your blogs new template.  Follow the instructions and you'll be on your way.

To make even more changes and personalization.  Go to "template" and click "edit HTML".  This will bring you to your blogs html.  Click anywhere on the displayed html, then hold the "Command" button followed by the "F" if you are using a mac. With a windows computer hold down "Control F". This will open a search on the html, allowing you to locate specific parts of the html.  Familiarize yourself with the structure of the html.

Blogging is not what I would call easy, especially when starting out.  I have found various websites and blogs that are very helpful.  Here's a collection of sites and sources to help you with your blog.