which I've since amended. I don't believe we can date Mark any earlier than 75 CE. Perhaps Mark was written in the 80s or even 90s, then Matthew, then Luke as late as even 140 CE.
Some resources I use for those who want to track down some of this yourselves:
Bart Ehrman books (misquoting Jesus is a good one)
Earl Doherty
G.A. Wells
Robert M. Price (the incredible shrinking son of man)
Wikipedia articles
online bibles such as blueletterbible (d o t) com
online Codex Sinaiticus
online Septuagint
Greek and Hebrew lexicons such as Strong's online lexicon
and just good old google search.