The Star Trek Chronology Project

The most interesting part of this is when TNG/DS9 and DS9/VOY start overlapping, and seeing exactly where things line up. For example, following being tortured by Cardassians in Chain of Command, Picard then visits DS9 and gets yelled at by Sisko for killing his wife. You can also see where the Maquis or Dominion plotlines are during Voyager's runtime.