I always forget how to import an existing project directory in Subversion, so here are the steps.

First, create the directory in the repository:

svn mkdir file:///path/to/repos/mydir

Second, checkout the repos directory:

cd /path/to/mydir
cd ..
svn checkout file:///path/to/repos/mydir

Third, add the directory content:

cd mydir
svn add *

Last, perform the initial import:

svn commit -m "Initial import."