Details/Info of each song

I have downloaded songs off the internet(itunes, limewire, torrents, etc). When they are finally downloaded and in my music folder, the details are not the way I like it. I right click the music file and choose properties. Then I go to details tab and delete all the information like title, subtitle, artist, album, year, etc. Then I click on the general club and enter in the artist name a dash and the name of the song. Example would be Elvis Presley- Jailhouse rock.
I do this for all my songs. I looked in my library yesterday and it seems all the details I had deleted are back in there somehow. Wondering if its a software thing or what. Any help would be greatly appreciated. And yeah, I know I'm O.C.D. when it comes to my music.
Also, is there a way to change or delete the thumbnail picture that is on the song. When I choose a song, such as Timbaland- Give it to Me and play it on Windows media player, the picture is a cartoon baby. Weird, but I did download it of Limewire.
Thanks to all,

First off, I hope you're careful with downloading songs, especially with programs like limewire...You could be clouded by spyware.

Anyways, from my experience, when you change the layout for one folder it should change it for all sub-folders as well (considering they're all set type as Music in Folder Properties). Here is one nice guide I've found that could help you out. I'm sure you could find more with a simple Google search.