There're zillions of articles about it, but almost nothing is a simple and step-by-step guide. Somehow I managed to figure out most of functions of Googlemaps Plugin (Joomla extension). What I got you can see here:
It's all nice...but I can't figure out how to change background color of the balloon (infowindow) from #fff to #ebf3fb (it's a color of page's sheet to match it better). I don't care whether it's a JS or a CSS-based solution, as long as it's easy to implement in Joomla!.
The weirdest part is that when I open Firebug, it shows that the lowest part in the middle of the balloon (the one that connects the balloon to the marker) doesn't belong to the same div style!