I have already covered all of the necessary topics to complete this tutorial, so I will mainly be linking to those articles.
Step 1) If you are running iOS 5.0.1 or below (which at the time of this article, is the latest version), the process is very simple. Just plug your iDevice into iTunes and click "Restore." Follow the guide here for a more in-depth tutorial. That's it; it's that simple.
Step 2) You will hopefully have your SHSH blobs saved. If so, then this will be extremely simple. Follow the guide here for restoring your SHSH blobs using TinyUmbrella. Then follow the guide here to continue with the restore.
If you run into any problems along the way such as error codes, search for them in the search box on the right.
If you have problems restoring, you may have to put your device in DFU mode. Follow the guide here for this information.
Post questions in the comments!