Cacher is the code snippet organizer for pro developers

cd /var/www/project/trunk
svn copy . ^/branches/whatever -m "new whatever branch"

# getting the branch code from scratch
cd /var/www/project
svn checkout https://www.project.com/svn-repo/branches/whatever

# otherwise you can easily switch a working copy to make it point to the new branch
cd /var/www/project/branch # this is an existing directory with a working copy inside
svn switch ^/branches/whatever