Venturit Inc., team released an open source wordpress plugin to include gmaps in posts and pages.

Download From WordPress Plugins Site

It uses short code, hence it is very simple to use, Just include this short code with your address, desired width and height of the map. [gmap a=”505 East Michigan Avenue,Lansing, MI 48912-1148″ w=”400″ h=”400″ z=”14″ i=”near” ].
a = the complete address
h = height
w = width
z= zoom (number range: 1-16; where 1 is the coarsest, or furthest away )
i = info bubble (options A => show, near => hide)

Above short code generates the following gmap.