Fortunately, there are sites that solve this problem and provide you some code you can paste in your site. Map Generator is very easy to use: enter the address, the type of map (street-level, satellite or hybrid), its dimensions and you could build a map like this:
My Maps Plus lets you embed personalized Google Maps by entering the address of the KML file generated by Google Maps. This way, you can showcase more than one location.
According to APCMAG, Google Maps will launch next week an option to easily embed maps. "First up, if you know how to embed a YouTube video in your blog, you'll be able to embed Google Maps in your website, Google promises. It'll be as simple as cutting and pasting a bit of HTML code into your website, just like a YouTube video. The embedded maps have the full functionality of Google Maps -- they provide satellite view, map view or hybrid view, and users can click and drag the maps around." They'll probably look the iframe included above and you'll see them in a lot of pages that provide contact information.
{ via Mashable }