Really depends on what you want to do with the Maps.
I've been investigating this area for a few weeks now and found tons of plugins.
I don't know in which format you have your DB, but a G search can help you out:
[ame="http://www.google.com/search?q=google+maps+wordpress+plugin&ie=utf-8&oe=utf-8&aq=t&rls=org.mozillat-PTfficial&client=firefox-a"]google maps wordpress plugin - Google Search[/ame]
In any case this one should do your trick:
Post Google Map Plugin for WordPress | WebDevStudios.com
SonnyCooL (10 June, 2010)