You want to recursively seek every unversioned file in a directory, and add them to your svn repository.
First, to list the unversioned files, you can use
$ svn st | grep '^?'
and to add all of them to your repository
$ svn st | awk '($1 == "?") { print "svn add", $2 }' | sh
As usual, you might want to check for sanity and run this command without the last sh
pipe first.
This recipe is the base of a script on github: svn-unvers.