Once you've got svn installed on WinXP, and once you've got Tortoise
SVN installed on WinXP, and once you figure out the url for the svn
repository on your server, you then can do what you said.
You might prefer to skip the windows gui (Tortoise) and write a
command line call svn in a .cmd file. You can then set up an icon to
run the command .cmd scripts, one to get and one to upload. And then
just click on them as needed. But this sounds like more trouble than
using the GUI for Tortoise.
Just remember that the 'update' icon in Tortoise means download, and
'commit' icon means upload to the server.
The other gotcha is that you first set up a directory with your stuff,
and then put it into the repository. Then you check it out, but to a
different directory. Then that second directory is your working
directory and the first directory is an orphan, never to be touched
again. Why they do this, I don't know.
A completely different approach would use WinSCP and/or ftp to upload
and download to the directory structure on your server.