How to insert album cover art on music files?

mapman,
Thanks.
Can any of these allow me to use my own pictures?

ozzy

Yes the dbpoweramp editor has an option to select image files you store on a directory on your computer. 
Picard might also not sure.  Never tried. 

Ozzy wav format might be an issue for what you want to do. Wav format is not inherently flexible with tagging. Never tried Wav with these tools. I started with wav and used dbpoweramp to bulk convert wav to lossless flac which is very flexible with tagging.  If tagging files with art and other info for usability matters to you I would suggest converting to flac.  

mapman,
Any audio degradation converting the wav files to flac?

ozzy

Technically, no audio degradation if done lossless at same resolution and a good quality streamer that works with flac format is used. Try it and see. There is always a chance some streamers do better with one format than another Even if source music content is identical, but should not be the case if done well. Some report differences case by case but has not been an issue for me. I have thousands of releases in my flac music library that I stream all the time and sound quality is never an issue.   Many were converted to flac from wav using dbpoweramp batch converter.  I’ve ripped exclusively Directly  to flac though in recent years