It'd be a lot easier to help if you provided more details. "Lose" is a pretty loose word, and could mean a lot of things.

What theme are you using?

The theme I am using is dotAwesome-cool by Vivid.

If you have any custom add-ons make sure they are up to date and are compatible with the new version.

Try checking your PHP error log and see if anything is coming up.

I checked the file error_log which is located in /www/ and I get the following message as one of the last entries:

[09-Apr-2013 09:32:18] PHP Fatal error: Call to a member function submit() on a non-object in /home/danweb16/public_html/updates/concrete5.6.1.2_updater/concrete/single_pages/dashboard/system/backup_restore/backup.php on line 66

What happened here is: I went to update concrete5, but I discovered the issue with the sidebar not appearing. So, I attempted to restore from the most recent backup. After having attempted a recovery, I received a fatal error and was not able to login to my site. I then deleted:
from: /www/config/site.php. But I don't know if this error is related to my disappearing sidebar.

Sounds like the database restore may have been incomplete. You probably need to step outside of c5 and revert your database by importing the sql backup file directly with phpMyAdmin.

At the moment, having edited config/site you have your previous version of the core code, but an indeterminate version of the database.

Yeah, I'm just a wannabe geek, so I think I'm going to need a complete step-by-step tutorial on this one if you don't mind JohntheFish? I dare not mess with my host database unsupervised.

There are too many little decisions you need to make for yourself as you go along on this, so there is no such thing as a one-track recipe.

This howto deals with backing up through phpMyAdmin. You could start learning and gaining familiarity by making a backup using it as a guide (and that will at least get you back to this point if a subsequnt restore goes wrong).

http://www.concrete5.org/documentation/how-tos/developers/backup-a-...

Then have a general read up on phpMyAdmin. There is a manual online you can google for.

The next step would be to practice using it on a development site (not on your live site). Gain familiarity before risking a live site.

Then you need the sql file you want to restore on your development system and with phpMyAdmin running on your live site database, go to either (depending on version)
- run sql, and run it on your file as an upload
or
- import sql, and import your file as an upload

Thank you for the info regarding the MySQL tutorial, but right now my main concern is fixing the update issue. Anyone know a fix for this?