Install some analytics software, google analytics is pretty easy to install.
Another good one is piwik, but you'll need to be able to log into the server, and manually upload files through FTP, and a MySQL database.
What exactly do you want to do with the domain? It's quite hard to make a profit just out of ads. Why don't you try to build a community and try to sell psychology related stuff in there? Maybe a dropshipping business may be a good idea.