...Hi....Not knocking Ramos excellent tute but just thought I give my thoughts on the matter.....this is for SRTM but you should be able to figure out other scenery addons from this.
..Here's a quick resume on how to install an area of SRTM.............
1. Download any SRTM area you want from SimV.to your desktop.
2. In either your Addon Scenery folder or your main Scenery folder make a folder with an appropriate name for the download you just did......eg. SRTM_Gibraltar.
3. INSIDE that, make another new folder and call it Scenery.
4. Place the .bgl file you just downloaded inside that new folder.
Start the Sim and go to the Scenery Library, click Add an Area and browse to the SRTM-Gibraltar folder and select it.
Click OK and then close and restart the sim........
That's it.
If you want to keep all your areas seperate then do the same for each area.......OR instead of as in the example, calling that folder SRTM_Gibraltar, just name it SRTM_AREAS or whatever,and Add it as I said......then any further area .bgl files you put in the folder with the Gibralter one will not have to be added seperately as you have already made the path.......simpler that way but easier to keep track if you keep them separate with appropriate names.
...Hope this helps.....commoner

Oh! BTW..you can delete the download from the desktop or wherever you downloaded to once you have installed ........