Movie Library CoverArt

I am newbie so bare with me. Probably a simple questions, but I just can't figure this out. I am scraping for movie information, using the IMDB but I am not happy with some of the cover art in the movie library. Is there a way to put my own image (jpeg) files in the same folder as my movies (which are ISO files) and have it get picked up. There is mention of changing jpg to tbn files, but that seems to be for the file thumbnails not the cover art in the movie library. I know I could probably go in and manually change it, but what I really want is it to automatically get picked up with a saved image file in the folder. Hope that makes sense.

File Thumbnail = Cover art

Does that mean that the *tbn file should pick up the coverart in the library, because that does not seem to be happening for me. Sorry for my ignorance here.

The first pic to be cached will become the "cover art".
If you have a valid *.tbn or folder.jpg at the time of scraping, XBMC should use that.
If otoh you add it after you scrape, you will have to change the "cover art" to it via the media information screen.

I understand what your saying, but I have valid *.tbn files in the directory with my movie files and to be certain that they would get picked up I deleted the "myvideo34.db" file so that it would force a new rebuild of the library database. However it seems to still pickup the cover art from the IMDB site. Is there a different file I can delete to reset this and force it to use my tbn files?

What version are you using and on what platform?
(remember, a debug log is a requirement for any problem report)