Could you help me find some websites that can tell me what the ingredients are in vinegar.

http://en.wikipedia.org/wiki/Vinegar

Vinegar is acetic acid. Some bottles are sold as 4% and some as 5%. White vinegar is straight acetic acid (distilled) and water. Apple cider vinegar has some of the ingredients (mostly flavoring) of apples. There sherry vinegar, rice vinegar, fruit vinegar, etc etc.
This first site tells a little about vinegar but not much else. That should give you a starting point. What most of these sites don't tell you is the trace of this and that here and there that gives the flavor. I hope this helps.
http://www.bellybytes.com/recipes/vinegar.shtml