Mashing Google Maps with Oracle Database - shows how to create google maps from datasets in a database
http://www.oracle.com/technology/pub/articles/schalk-googlemaps.html

Use decimal/numeric for storing lat long values. Apparently 5 digits after decimal gives 1 metre accuracy.

There was a project spatial-db-in-a-box or something I should look into, which shows how to use GeoTools with non-spatial databases.

SQL datatypes: http://www.sql-server-helper.com/faq/data-types-p01.aspx