Manual metadata entry and music metadata

I have a couple of questions for anyone who could answer them.

 

Some of the movies and TV shows I have on my NAS, when ATVFlash fetches the metadata, the information is wrong and continues to be wrong. I know you can manually input metadata for movies and TV shows but what happens if it’s a ripped DVD? Which folder do I store the XML file in? The main Movies folder, inside the DVD folder or inside the VIDEO_TS folder? 

 

Secondly, some of my CD’s that I’ve stored on the NAS the cover art and information it fetches is either out of date or the cover art is low res and terrible. Can I write my own metadata for my music?