What is the default folder structure for an iTunes library? I have OS X 10.7.6 and I run iTunes 11.1.3. (8)

I moved my iTunes library to a NAS and kept the indexing files on my Mac.

The folders I find on the NAS looks as follows on the same level in my Music folder:

#recycle, iTunes Media, Library

Should I not just have one folder, iTunes Media?
If so can I delete the other two, #recycle and Library?
Indeed, the only folder that iTunes uses to look for media by default is iTunes Media.

However, that doesn't mean that you can simply delete those other folders. You might be referencing files from those folders in your iTunes library. Check those folders for music, and only if there's no files you need in there, then delete them.