If you are running an Linux system, there's packages that make it quite simple. I think that if you do a server install on Red Hat or its relatives (Fedora, CentOS, etc.) that it installs by default.
I think under Ubuntu - at least the install I did - you had to install subversion manually using apt-get, synaptic or whatever your favorite tool is. The package is named either "subversion" or "svn", I forget which, so try both.
The same package supports the client and server subversion software. Once it's installed, create a repository using the instruction manual as a guide, open up the firewall if you need to, and
you should be in business.