American wanting to travel to Cornwall, no idea where?

Train would likely be your best way to get there. London departure point is Paddington, which is where the Heathrow Express and Connect terminate, so an easy-ish transfer. There is a flight to Newquay, but it's from Gatwick and on an airline that I don't think offers many codeshares, which makes transferring more difficult.

As for Cornwall itself, I don't know the place too well but immediate thoughts to me are Penzance, St Ives, St Austell, Truro and Redruth. Like I say I don't know much but it's a starting point.

Cornwall is indeed a wonderful place. Because of its geography and road network, though, it doesn't really lend itself to one central location. The only city in Cornwall is Truro, so that is where you'll find the largest selection of groceries as well as lodging options. Truro is accessible by train from London.

If you rented a car in Truro you could drive around and see quite a lot of Cornwall's lovely scenery and points of interest. Don't miss St. Michael's Mount -- it is really magical IMO.

The most economical flights from the USA are generally to London, so you'd fly into one of the London airports and then connect by train to Truro. Another way to save money is to avoid Cornwall's summer peak tourist season. Yet, in winter the weather can be pretty miserable and some B&Bs, museums etc. are closed. Spring/fall shoulder season is advantageous in terms of prices and avoidance of crowds, especially in the spring when the days are longer.

I've not been to Cornwall so can't share any personal experiences but here is a link to some recent threads about Cornwall on this forum. Maybe you can get some good information and ideas.

Cornwall was really hopping last August. From passing comments I heard, I gather that the Poldark and Doc Martin TV shows have caused an uptick in visitors. In the coastal towns I found it difficult to find a place to have dinner--even a simple dinner--if I had not made a reservation. I enjoyed my time a great deal, but it's definitely not a place to try to make last-minute lodging plans during high season.

I stayed in Mevagissey (St. Austell was fully booked) and visited the Eden Project and Lost Gardens of Heligan from there. Mevagissey is small and doesn't handle vehicular traffic well down near the waterfront.

I stayed longer in St. Ives, really overdosing on the art galleries and museums.

I spent a forced night in Truro because of difficulty in booking the coastal towns. Truro is very attractive, definitely worth a visit. It doesn't have the in-your-face level of tourism you'll observe in the coastal towns.

We have visited Cornwall several times. Due to its shape (a very long skinny peninsula), it really doesn't lend itself to staying in only one location. You will be spending too much time driving back and forth. I suggest you choose one location at the western end (we chose Zennor) and one at the eastern end ( we used Mevagissey). The western end, the Penrith area, is full of megalithic sites and beautiful coastal views. The eastern part of the peninsula has more castles. Good places to visit on the eastern end include Bodmin moor, Boscastle and St. Isaac. Tintagel is good for the castle (LOTS of steep, slippery steps to climb) but the town itself lacks charm. The little villages east of Mevagissey are very charming. Penzance is big enough to have very annoying traffic.

All of our visits have been in June, before British schools get out for summer holidays. I have heard the area is very crowded in July and August since many of the British spend their holidays there.

You really need a car to visit Cornwall.

I think Cynthia has a good idea to split your Cornwall time with two bases, east and west. Truro might be a good choice for one. We stayed three nights in Penzance, which wasn't a very appealing town except for nearby St. Michael's Mount. You'll definitely want to be driving. Cornwall's topography is basically hills and valleys running north and south, so driving east or west takes time. That topography is what created all the natural harbors that made it so attractive for fishing and smuggling, and also what kept the Romans from conquering it. The Saxons also had a hard time getting into this Celtic stronghold.

You don't have to go to London to get a train to Cornwall. There is a bus service from Heathrow to Reading, where you can get the Great Western train to Devon and Cornwall. From Reading to Penzance took us about five hours. You could break the journey in Exeter if that's too long for your jet-lagged arrival day.