I gave up on installing Worpress from the repositories. It was much easier to install from the packages at Wordpress. From what I gather ( which isn't much
) Debian moves the whole package to /etc/wordpress or something like that, and the plugins are not aware of those changes. I've seen some symlink fixes, but the education needed to get it going was at odds with my impatience.
I could probably figure it out now, but at the time LAMP, Debian and Wordpress presented me with far to many questions.
Give it a shot with a vanilla Wordpress install, and work it backwards if you really need to know.
Good luck !
PS The automatic updates from Wordpress will not work ( down the road ), and neither will updating the plugins work, from a repository install.