Version control is one of those things that becomes pretty indispensible with larger projects. Especially as you add multiple developers into the mix. SVN happens to be a long-standing favorite of many people that is pretty simple to setup and use.
Here's a quick reference for creating a new SVN repo:
First, verify that you have SVN installed. You can check your package lists, or just type:
which svn
to make sure that it comes back with a valid path. If it's not installed, you should go ahead and do that (on debian you could apt-get install svn, for example.)
Create the repo
Let's say we wanted to create a repo called bigcatrepo:
svnadmin create /var/bigcatrepo
Edit the config file
vi /var/bigcatrepo/conf/svnserve.conf
make sure the following is in there:
anon-access = none
auth-access = write
password-db = passwd
Run the svn server as daemon
$ cd /var/bigcatrepo/
$ svnserve -d