I\'ve been using various source control systems for a while, but when it comes to reverting changes I\'m not yet an expert. Can someone help given this scenario:
I assume you are using TortoiseSVN in my answer.
I don't think your scenario will lead to a roll-back of the files, because you still want to preserve the history of each file. Most of the time, what you are going to do is just find and fix the bug and commit a new change to this file.
If you want to compare two revision, it's pretty easy in tortoiseSvn, right click on the file, then go in TortoiseSvn->Show Log. Then select both the revision you want to compare, right click and then Compare Revisions.
If you want to find who is responsible for the bug, you can use the menu item Blame in TortoiseSVN... This will let you know who modified each line and at which revision.
Oh and if you want to revert a file back to a previous version, you can do so in TortoiseSvn->Show Log an then you select the revision you want to revert to, right click and select Revert to this revision.