Newbie Qn re Basic Google Maps Mashup How To?

I want to create a page that displays a map based on a place name
entered by the user - e.g. Golden Gate Bridge gets a map of San
Francisco, centered on the bridge - pretty basic.

What GEMS/packages do I need to install for this? Any gotchas I need
to think about (apart from duplicate place name resolution).

Any sample code would also be helpful. FWIW I'm thinking of Google
maps rather than Yahoo maps for this, but either is probably OK.

TIA,
Brendan

Have a look at mapstraction, it is a javascript library that provides
a supplier independent API to google, yahoo etc so you can develop
your application and decide late (even at run time) which map supplier
to use.
See www.mapstraction.com

Colin