Diane,
Thanks for the link to the 21 day Italy itinerary.
Wow! This would be a whirlwind type of trip!
There are too many destinations & not enough time to explore such destinations.
I agree with Zoe in terms of using the itinerary as a guideline but then tailor it to your own interests & pace.
Angela's advise is spot on!
If I had 21 days & had never traveled to Italy before, my itinerary would look something like this:
Venice (3-4 nights with day trip to Padua-26 mins. by train) > Florence (4-5 nights with day trip to Siena or Assisi) > train to
Cinque Terre (3-4N) with day trip to Pisa/ Lucca > Sorrento, AC,( 4-5 N) > Rome( 4-5N with day trip to Orvieto).
If you want to visit one of the major lakes in northern Italy, you may choose to fly into Milan then head to Varenna ( Lake Como) or Stressa( Lake Maggiore) on the day of arrival as it's an easy train ride that will take you about one hour.
Then you can go to Venice & just carve out 2-3 nights from the rest of your itinerary & add to lake destination.
You are so right-- So much to see and so little time!
Check this website for train schedules: http://www.trenitalia.com
Check this website for detailed info about train travel, how to buy tickets, etc: http://www.seat61.com
Happy planning!
Edit: check this website for transportation options: http://www.rome2rio.com