I want to play an adventure map with my friends but want to do it over my server so we don't need to use "Lan". How would I move the map into my server from my desktop?
I'm going to assume that you're running the server on your computer.
To use a map on a server, all you have to do is navigate into your saves directory within .minecraft, copy the folder containing the map you wish to use and paste it into the server directory's saves folder.
After that, you will need to modify this line in the server.properties file:
Change 'world' to whatever the name of your map folder is.
Hope this helped!