The bottom line is that everyone should be on the same page. Everyone should know what the current task(s) is/are and when each task should be done. Everyone should understand what others are doing in case changes become necessary.
Now, you don't have to tell everyone about every line that is changed in software. However, if your change affects other people, you have to notify people who will be affected. Version control is complex all by itself. However, you can (properly) use some tools to help make that less complex. I suggest the use of CVS for version control. This software can be run as a server so multiple developers can access the repository concurrently. It also allows non-conflicting changes to the same file. Best of all, it is robust and free!
Save your email messages so you can refer to them later. Make a folder so that Micromouse email does not mess up your main email folder.