Train Travel from London to Edinburgh then on to highlands ? Suggestions

yeah rail will be easiest on the pocket and nerves.Prebooking it a must to get the cheapest seats.
I find this site useful.
http://www.railsaver.co.uk/bookmarkRPPC.html
there are limited overnight cheap"bargain berths" if you look through scotrail
Megatrain route via birmingham-edinburgh might be usefull, fares can be as low as £5.
Theres a scotish -rail rover ticjket for about £100 gives 4 days unlimitited train use.

Theres aslo a "sail-rail" ticket from many stations, say manchester.this gives train ticket to Holyhead then the ferry ticket to Ireland,runs at £29 if I remember correctly.
The rail trip to to Fort William is a must, one of the must scenic in europe.
If you really love travelling, I'd trade the aviemore bit for a trip up to Wester Ross,theres a tour company out of Inverness runs daily,Its a wild old place, the emptiest bit of europe

Just for comparisons, look at national express: http://www.nationalexpress.com/ It covers bus, trains and coaches. Skyscanner : http://www.skyscanner.net/ lets you look at cheap flights. Once you have all the available info, then you can decide which is best route to take -bus, plane, train, coach.

When I was in Aviemore I had a car. It takes about 1 hour to see Aviemore. After than, you need to get out and about. A car was necessary for this.

Inverness is a nice little town. Look at Ardgarry B&b for a great place to stay. Johnny Fox pub had wonderful entertainment each night. Hootnanny used to be good, but they are not anymore. Try Bellhaven Ale while there. It is the oldest brew house still making beer in Scotland. We took the coach tour from the Tourist Center in Inveness-http://www.jacobite.co.uk/ It went to Loch Ness, etc. To do anything else around Inverness you will need a car also. I think you might be able to book other tours at the Tourist office. Email them and ask. You might want to look at this: http://www.scotland-inverness.co.uk/inverness-trips.htm

You are doing are favorite trip in Scotland. You will LOVE Aviemore. There is a local micro-brewery that gives tours with free samples- just a bit of a walk from the center of the village. We like to stay at the Royal British in Edinburh. It is across Princes St. from the rail station. In Aviemore we stay at the Caringorm- also across the street from the rail station. It looks like a little castle and has marvelous food. There is much more than an hour's worth of things to do there. Take the funicular up the Caringorm and see some awesome alpine scenery. There are nature walks, horseback riding, etc. There is a steam train (restored) that does a 1 hour (appx) round trip to Boat of Garten and back. You can also arrange some private tours- check out highland tours on the web. There are some whisky distilleries within range also. Inverness is also great and you may want much more than 2 days there. We stay at the Royal Highland (station hotel again). Do day trips to Culloden and clava cairns, Boat up Loch Ness and see Urquart castle, boat out on the firth, day trip to Isle of Skye and Eliean Donnan castle, Great Glen, Glen Coe, even day trips to Orkney! Feel free to private message me!

I agree with John. We utilized National Express and got a very good fare London-Edinburgh-London. The trains are comfortable and the station is in the center of town. It was our first trip to Edinburgh so we jumped on the HOHO bus to get acquainted with the sights and layout of the city. I wasn't impressed with the commentary (technically, the content was fine) but we had packed our lunch and ate it on the bus while it made the full tour then on the second go around we got off at the different stops. The Edinburgh castle was amazing and the views are phenomenal! We didn't go on to the highlands so I can't help you there. Hope you have a great trip.