Riomaggiore
The largest of the villages is Monterosso--which seems to be cleverly modeled after the Pirates of the Caribbean at Disney Land--or is that vice versa? Really--only one thing comes to mind upon entering the narrow streets with their tall, vibrantly colored, narrow buildings--pirates--this must be where they pillaged and hung-out between forays on the open seas. It is so "piratey."
Each of the villages is a little different while being the same. For all of them, except Monterosso which is the largest and most developed, the mystery is "why?" Why are they there? Why were they created in the first place, centuries gone by? They must have been self-sustaining as contact to the "outside" was difficult at best, impossible much of the time. The obvious answer is for fishing--but then, for whom did they fish? Where were the markets? Most certainly people did not drop by to buy the day's catch. Today the idea of totally closed, self-contained groupings of people is most often seen in strange sects and cults, making it difficult for the rest of us in the third millennium to understand places such as the Cinque Terre.
My suggestion is to take the ferry from a starting point in either Levanto or Porto Venere, stay on the ferry the entire way to the last of the villages so that you can have an uninterrupted introduction to them. After that you can backtrack via the trail, the ferry or the train to each of the other four.
It pretty much takes all day to explore these villages--even though they are small. Of course, you will lunch at one of them, have gelato on another, enjoy their ambience as you stroll the lanes, maybe shop for some gifts or souvenirs and then have the timelines of ferry and train schedules. While lunching, you can watch fishing boats being hoisted in the water or ripples lapping the rocks and stones of the beaches.
Another thought I had as we enjoyed the day is that it would be fun to spend a night in either Monterosso or Vernazza--to experience these villages at the close of the day when all of the rest of us tourists are gone, would be nice. We stayed in Levanto at a lovely place--Villa Margherita--but, if we go again, one night will be earmarked for a night with the pirates.
If you have never been to Cinque Terre and find the literature to be confusing as to how you visit the villages, know that it is very easy to do. It is not any more strenuous than visiting hill towns of Tuscany--less so than for many of them. It is not necessary to hike if that is not your thing. You disembark either the train or the ferry at the foot or in the middle of a village.
One caveat is that the ferry does not stop at Corniglia--you have the option to hike there or to take the train. If you take the train and don't want to walk up 300+ stairs, there is a park bus that will make it much easier on the legs--so even this highest of the villages is easy to reach.
We found Levanto to be a perfect staging point for the Cinque Terre. It is easy to get to--no city traffic to fight in order to get to its heart. It's easy to walk around in; there are good restaurants and a free beach--along with the regular European type beach clubs where you rent lounges and umbrellas. The Villa Margherita is very nice, away from noise and traffic, has its own parking, serves breakfast and is owned by very nice people. I would go back there in a heartbeat.