Hi, Paulco, a good place to start is in thsi thread, Origins: Found on the Mudcat, which has an alphabetised list of links to various discussions on songs' histories.

You will most likely get some answers in this thread, but you'd probably get more if you were to start a separate thread with a more specific title for each one.

Good luck, these are the kinds of questions which bring about great discussions here, so thanks for asking!

kat