Read the Squid Log?
Please elaborate what you want exactly. I can think of several options, like creating some default queries, that give some insight in how to use the logs.
This can give output in plain txt or in a graphical way (like pie/collumn/etc)
Anyone has thoughts on this subject?
You will find squid reports under Web proxy stats from the day after you enabled the proxy (stats are created during the night).
Still, I feel it difficult to display the log squid, and a page where I could add the refresh_pattern, to can add some settings.