The thing I really like about the table on that page is how each command is linked back to an HTML version of its man page. This is really convenient, especially for the feeble minded.
There’s another page, CVS Concepts that does a deeper dive into the differences between cvs and hg, particularly in the areas of workflow and server operations. Highly recommended.
Quick reference cards and cheatsheets can be found on the Quick Reference Cards and Cheat Sheets page.