alert sounds for POI"S

Hello everyone, would anyone be able to assist me on how to attach an alert(sound/icon) to a poi I've just downloaded, I'm not sure if you need to make an new folder for the alert or have both in the same folder as your poi's........once I solve that issue do I copy the name of the poi and attach to the alert?? I think I'm close but would appreciate a little help. Sorry I'm not the most knowledgeable person when it comes to computers .