I'm using EE 1.7.3, and I'd like to know how many articles are present in my site (there are thousands, want an exact number). Where can I find this?
In the control panel go to Admin › Utilities › SQL Manager › Database Query Form
In the query form put
SELECT COUNT(*) FROM exp_weblog_titles;
This will give you the total number of entries on your site.
If you would like to know the number of entries in a specific Weblog you can do
SELECT COUNT(*) FROM exp_weblog_titles WHERE weblog_id = X;
Just replace "X" with the weblog_id of the Weblog you are interested in.
NOTE for EE v2.x users: alter the SQL by replacing "weblog" with "channel."