This one might just spare you about 2-3 hours of your time doing SVN+SSH kdesvn googling. One would think it would work out-of-the-box, but it doesn’t. To get kdesvn to work with SSH, there is one small undocumented trick – using an environment variable (as if you were using command line SVN+SSH). To do that, put the following line into your .bashrc:
export SVN_SSH="ssh -l <your_remote_ssh_username>"
If you try using SVN+SSH without it, kdesvn will try to login to remote server using your current username (the one you are using on your local machine). Of course, each time unsuccessfully because it’s not the right username. After that, go to Subversion->General->Checkout a repository, and enter:
…in the URL field. Also, choose the target directory and check any other desired options. After that, just bookmark the connection and you’re all set up.