It's been a while since I used Tortoise, but if I recall correctly it comes with the svn.exe file - you will need to find that file within the Tortoise installation directory and add the directory containing the svn.exe file to your PATH.
I don't see a standalone svn.exe in my install either. I recommend installing a SVN standalone client if you want to use a client. Collabnet has one. You want "CollabNet Subversion Command-Line Client v1.6.5 (for Windows)" I'm sure there are others too.