I am looking to go from Vernazza to Venice via train in September and I am having a hard time figuring out which train schedules I should be looking at and what are the fastest trains. It seems like it's a 7 hour trip but I'm having a hard time figuring it out. Which websites should I be using?
use the trenitalia site, but don't try to look at September yet, the schedules are probably not up yet! Check the schedules for the next month or so to see what the options will likely be- but I sincerely doubt you'll be on 7 hour train, so don't worry too much. There's another site than I am now blanking on that contains all the European schedules, I'm sure someone else will come along with that. Good luck!
Most of the european train websites show routes in all the countries. Many people will recommend the German one (bahn.de) but I find the Swiss website (sbb.ch, or rail.ch for English) easier to use for planning purposes. Trenitalia is my least favorite!
As Kelly suggests, use a date in the next month or two---September is too far out to look at schedules. They will change little if at all.
It looks like the shortest route is through Pisa and Firenze, with a travel time of 5.5 to 6 hours. Going north (via Genoa and Milan) requires fewer changes but takes longer.