Dumb Question re Herald/Vitesse, etc

[Paulsv@aol.com]

Dear Scions-
Sorry to ask such an elementary question, but hope you'll forgive and help.
 I've always been a TR man, and have some knowledge of Spit's, but I am
woefully ignorant about the Herald, Vitesse, and Sports 6 line.  How are they
related, how do they differ, and when were they made?  What engines do they
have?  Are they related to the Dolomite and 2000 sedans?  Can you suggest a
good source for this and other information about these cars?  Thanks for any
help, and don't tell my wife!!!!
Paul