But won't that overwrite a file if you have one that is the same? For instance lets say there is a file that you edited and I also edited the same file. I commit mine first thus replacing the old one with a new one. If you update first then you get the new version and then when you commit yours which is old won't that then replace the new file with an altered older file?
No yours should have had a "red" checkmark by it, and will not be overridden.
I thought that if you did not update the SVN can see that you have an old file compared to anything new you have not downloaded yet which will either warn you the file has been changed and/or merge the two files together (if possible).
All you need to do is go to SVN, right click on it and to a "compare to working copy."
If you update before you commit isn't that basically conforming to the SVN that "yes I know stuff is new but I want to replace it with my new stuff" even if your "new stuff" is actually old stuff with some tweaks.

