We will be flying into Manchester Airport from Atlanta in mid-May. From there we are going to Oxford for a few days, then up to Newcastle, and then back to Manchester Airport for the return flight home. What are our best options for traveling between the airport and these cities? Our other option would be to fly into London, then to Oxford, then to Newcastle, then back to London. Thanks for any and all suggestions.
For that trip, I suggest renting a car.
If you're not planning other explorations with a car, then I would take trains. Trains run direct between all these destinations, except that you do connect in central Manchester to get to/from the airport or would also connect to/from a London airport. You need not fly in and out of the same airport, if you book a "multi-city" flight plan.
You could do this with a BritRail England pass for 3 days in one month at $228 per adult (or less if you have 3 or more people, or people under age 26). That link also discusses advance-discount fares and other discount cards.
As you aren't visiting anywhere around Manchester it doesn't seem that good an entry point.
I'd be looking at Heathrow->Oxford->Newcastle->Heathrow (or some other airport with a transatlantic service - maybe a Sky Team hub since you are coming from Atlanta). Last trip by air the rest by train.
I would fly Atlanta to Newcastle via LHR, AMS or CDG
train from Newcastle to Oxford then home from Heathrow
(or vice versa)
I think the OP likes the fact that there is a non-stop on Delta.
"I think the OP likes the fact that there is a non-stop on Delta."
maybe - but it's not particularly convenient for Newcastle and Oxford
Go on www.nationalrail.co.uk to find the train times between Manchester Airport > Oxford; Oxford > Newcastle & Newcastle back to Manchester Airport. (Fares are cheaper if booked in Advance - say 11 weeks ahead - for specific trains - or use Britrail Pass - compare price)!