It is very simple to check out a repository.

Simply navigate to the folder you want to checkout into and run this command

cd /home/sitename/public_html/
svn checkout file:///home/svn/repos/project/trunk .

. means place files in the directory you are in.

You can also checkout from a specific revision. For example you at at revision 500 but you want to checkout from revision 432 (for whatever reason).

svn checkout file:///home/svn/repos/project/trunk . -r 432

What if the repository is not on the same server???

svn checkout http://www.sitename.com/svn/repos/project/trunk . -r 432

http:// or svn:// or svn+ssh can be used depending on your setup.