Although you will need a Google account to create one, annotated maps can be made and shared publicly on to those who have a link – the same model used in Google Docs. It is also possible (like a Google Doc) to share editing between a group of people, though each will need a Google account.
Its most obvious use is in creating place marks to which you can add text, images and videos. More than one image or video link can be added to each point. So it would be possible to add – say – an introductory piece created by yourself, followed by further images or videos.
Possible scenarios for use include an annotated guide to an area for students or created by them and data capture by students or staff for inclusion into a more professional system. Please note, Google Earth does not display the embedded video and image data but the links are contained in the ‘ExtendedData’ element of the KML so could be re-coded.
Here is a link to my Birmingham visitor’s guide as an example of place marks with embedded video and images:
It is also possible to add lines and directions, but these can be a little tricky and unpredictable. A little more practice may be all that is needed though.
From January 2016, Google is ending the Maps Engine Service so you may not be able to create a new free account. Its simplest alternative is My Maps, which has almost identical features but allows maps to be saved directly in Google Drive and shared in that way (so you will need a Google account). Here is an example map. It does have a built in video and image search and direct links to image urls and YouTube videos which make it very simple to use for less technical users.