The first thing you need to do, is go to Google Maps and search the location for the map you want to add to your website (in this example I've used "london crowne plaza").
1. On the top right corner you have a link labeled "Link". A box will pop up with both the direct link to the map, and a line of the HTML code.

2. Highlight the HTML code and copy it to the clipboard (CTRL+C).
3. Insert the HTML code into your website's HTML code.
4. Optionally, there is also a link offering the option "Customize and preview embedded map," which you can use to change the size of the map you will embed.
5. On the bottom of the screen, you have the HTML code you need to insert into your website's HTML code.
6. All done. You can now check the live version of your website to ensure that the map is showing properly. It should be fully functional. For example, when you click on the map, it should open your map from the Google Maps website. If your map is not working properly, you can find troubleshooting support on the Google Help Center.