You can get loads of good deals if you buy in advanced 0845 48 49 50, if anyone going is a student then it may be a good idea to get a young persons rail card as you get 33p of every pound you spend.. Hope that helps
if you are travelling on either weekend day, you might find it quicker to fly (due to having to take a bus for part of your journey), and it might even be cheaper.
Sorry forgot to put we are travelling from Huddersfield, West Yorkshire. We have looked at flights but they are expensive,maybe because it is middle of July.
I wouldn't recommend flying when you're only coming from Huddersfield - by the time you've got to an airport at one end and then got in to Edinburgh city centre from the airport at that end it would be much quicker to take the train. Best bet I would think would be to get the train from Huddersfield to York then get on the GNER east coast mainline from there straight to Edinburgh. Go to www.gner.co.uk and you can book really cheap fares - singles are often cheaper. I recently got from London to Edinburgh for �10 one way and �15 coming back.