Journey from London to Inverness- Advice Please

Okay, so my parents have booked flights from Boston to London for early October for 2 weeks.  I'm very excited.   They've never been outside of the US/Canada.  With 4 kids, 2 weeks of vacation, and absolutely no money, we never went anywhere.  And now, there is still no money to travel, but they've been saving their pennies for years and this is their 30 year anniversary present to themselves (with help from us kids!).
They're going to fly in London and I told them I'd meet them in London and we can make a journey through England and Scotland all the way up to Inverness, so that we can see the sites. We'd like to spend about a week or so making the journey up this way, so we can only see highlights.  We'd preferably like to travel by train, but I will drive if necessary. (But I don't want to drive to London first to meet them, so I would hire a car and drive up probably)  We'll spend the other week up here in Scotland, taking small trips to the Orkneys, Isle of Lewis, etc.
So if you were taking a journey from London to Inverness, what would you stop and see?  Anything spectacular we need to keep an eye out for?  We don't want to spend more than 4 hours travelling at a time if at all possible either.  So any thoughts?
(We may do the reverse as well, start in Inverness so they can used to the time zone, etc, and then do the majority of traveling the second week, going from Inverness to London)
Cheers!

I would go via the Cotswolds andWales! Some beautiful scenery there. But if you're going a more direct route, one place that springs to mind is York.

The Lake District is lovely, too! A few years ago, I drove up from SW Wales to Stirling, and stopped overnight in the Lake District.

I went  London-Inverness-Sheffield about 3 years ago.  Here's the route I would suggest for you guys (assuming you're going by train):

London
Bath (go to Stonehenge if you can make it, skip Stonehenge if short on time)
Peak District ( via Birmingham New Street to Derby or Sheffield and daytrip to the Peaks)
York
Edinburgh (if you're not already going in Week 2)
Inverness

Thanks! Great ideas... 

I'm open to more, as I want to make sure we're hitting all the highlights ;-)

Okay, maybe thinking of doing a combination of hire car and train... 
So, I am assuming that car hire places will let you pick up one place and drop off in another, like a lot of them let you do in the states?  Oh come, to think of it, I did that in Ireland, so I would imagine its fine, maybe depends on the company.

My mom wants to see everything, hahaha, which of course isn't possible.  Only real requests so far are Stonehenge for mom and for dad, seeing some Beatles' stuff- either in Liverpool, or at least Abby Road Studios and a few London Beatles' sights.
We're also thinking of heading into Wales for a day or 2.  Too much to cram into a short amount of time! 

This is really tough for me to plan, because I haven't been around the UK (minus London) at all-but  this gives me an opportunity to see it too, so this is as much sightseeing for me as it is them. 

A friend and I did a whirl-wind British Isles trip 15 years ago.  We started out in London and took the train to Bangor, Wales.  Spent the night in Bangor and part of the next day.  Took the train to Holyhead and the ferry to Dun Laoghaire, and spent the next two days in Dublin.  From there we took the train to Belfast and the ferry to Stranraer.  We spent the night in Stranraer, and then the train to Edinburgh, for a couple of nights.  Then the train up to Inverness, spent two nights and caught the train back to Liverpool.  Spent the night in Liverpool and spent the next day doing the Beatles tour.  Took the train back to London that evening.  We did the whole trip on a Britrail pass, and stayed in B&Bs that I found in a guide book.  We didn't have a lot of money, but we had a blast.

It might be hectic...but I think you could hit most of the things you and your parents want to see!

Thanks, that sounds good too...hmmm.... so much to see!

I think you would be better using the car the whole time so if you see somewhere good to stay you have the option. I would suggest heading west perhaps Bath, Cornish coast etc then looking at Wales (perhaps tenby, Snowdonia etc), back into England and perhaps pick from Cambridge or Oxford, Cotswolds, Lake District etc. I guess it depends on whether you want to see cities or countryside - the car will give you far more freedom me thinks... unless you have time to explore one city can seem quite like another.

If you're going to York, the Yorkshire Dales aren't that far away...

Sayeth the girl who's spent one afternoon in the Dales and is now a raving fan.

Excellent