At first, you have to read SVNBook and learn how Subversion works.
TortoiseSVN is just a mere client, i.e. it does not allow you to access your local repository remotely. You have to use Subversion server to expose your repositories over the network (e.g. use Subversion + Apache HTTP Server or Subversion + svnserve
).
You can setup your server from the scratch or use such package as VisualSVN Server that allows server installation and administration to be done in very user-friendly manner.