Setting Up Google maps. HELP!

Hello
I am trying to set up a GMap situation where people can login and give their location and some other information
when people scroll over the marhers a popup gives more info and an image

i installed gmap and location modules, but am getting errors saying that it cannot find location module in the database
i am assuming that this will be filled in when peopl ebegin entering lat long info.
am i right.
what is a way to make this work

Thanks in advance

chetan