Updated CONTRIBUTING.md, added text on forking a repo.

Author: hpodzorski-USGS

CONTRIBUTING.md

@@ -32,9 +32,15 @@ The second approach is making your contribution directly in the GitHub website.
 
 ## Forking the repository
 
-Independently of the approach you choose, the first step is to fork the Python Packaging Guide repository into your personal GitHub space.
+Independently of the approach you choose, the first step is to fork the Python Packaging Guide repository into your personal GitHub space. To "fork" a repository in GitHub means to create a copy of the main repository, or repo, that you have complete control over and can modify as you see fit.
 
-*__TODO__: This section should show a beginner user how to fork a repository in GitHub.*
+To fork a repo, 
+
+1. Make sure you are logged into GitHub.
+
+2. Go to the repo you would like to fork, in this case the [Python Packaging Guide](https://www.github.com/pyopensci/python-package-guide) repo.
+
+3. In the top right-hand corner of the page there is a 'Fork' button. Click that button. You will be brought to a new page where you will 'Create a new fork'. Feel free to keep all the default inputs and click 'Create fork'. This will create a copy of the repo at `https://github.com/<username>/python-package-guide`, where `<username>` is your GitHub username.
 
 ## Contributing via the GitHub website