How to Install a Adventure Map in Four Easy Steps
Next you download the map. To do that you click the download link and and it will take you to a website called addfly. Just wait 5 seconds and then click the skip add button in the top right corner. Now you click the download now button on the website you are on. Now if you are in internet explorer you click the open button on the screen.
Now you will see a file on your screen with your map name that you downloaded. Now click the start screen but still don't close the file screen and type in the bar %appdata% and click enter. Now click your .minecraft folder. When in it click the saves folder (if there is not one just make a folder that is called saves). Now copy and paste your map into the saves folder.
Now all you need to do is go into your minecraft singleplayer and there it is.