I have updated my plugin which allows to display Google Maps in WordPress blog pages and posts. I am pretty sure the plugin is the most easy to use amongst several others which exists for the purpose.
The idea is that you just find a location you want to display on Google Maps site, get a permalink to that map, and then link any text in your post to that Google Map permalink.
There is more info along with step-by-step guide on my site. Have a look if you're interested.