RE: How do you sort yours....?
Currently I have all of my books on my kindle in collections of; Read, New, Current and then any authors whose work I always buy (series etc), I have collections for those by author name.
It seems that Amazon don't have a way of backing up collections as yet and that Calibre is the way to go for keeping from having to redownload and re sort everything when you upgrade, so I'm off to look at that right now.