I know that using tables is bad for layout except for tabular data, but I had no other options than using tables for this particular page (see screenshot) layout. Also, I am new to web designing, so some ideas about how to slice up the page using div could help me start with the right foot.

The website is: http://test.cdms.net/Ecosight

You will see the login page. If you login using test, test, you'll see the second page with a very slow loading map. Both pages have been structured using tables.