A591 to Keswick, then either A66 and pick up the old A6 at Penrith (my own preference), or continue on the 591 to pick up the 595. Both routes get you to Penrith. From there, the A7 north is a pleasant (but not fast) route through the Southern Uplands. You could use the motorway to get to Gretna if you wanted to visit that town and then come back across to the A7. That will take you through Langholm and Hawick into the Tweed valley at Selkirk with several interesting small towns (dowriver to Melrose, Jedburgh and Kelso, upriver to Galashiels, Innerleithen and Peebles) and from all of those good cross-country roads to Edinburgh. Alternatively, from Langholm, there are B roads through unspoilt upland countryside via Innerleithen all the way to Edinburgh.
Slightly quicker, leave the motorway at Moffat to pick up the A701 past the Devil's Beeftub or the 708 past St Mary's Loch to Peebles or Innerleithen again.
"Both routes get you to Penrith" - I meant "Carlisle".
At Penrith take the A686 which goes through the Eden Valley, up to Hartside then over to Alston.
From Alston take the A689 towards Brampton but leave that road after 9-10 miles to cut across to Greenhead. At Greenhead take the B6318 which follows the line of Hadrians Wall and passes Housesteads Roman Fort. Worth a visit if you have time.
When this road crosses the A6079 take that road through Chollerton and then when it meets the A68 take that up to Otterburn.
At Otterburn look out for signs for the B6341 to Rothbury and at Rothbury follow the signs to Cragside House NT (again worth a visit if you have time). Shortly beyond this, you'll meet the A697, which will take you up to Edinburgh through the Scottish borders.
Well, that's what I'd do, but there are probably others with a better knowledge of the area. My route will take you through an attractive part of the Lakes, over the Pennines, along Hadrians Wall and through an attractive area of Northumberland.
I'd second Ursa's route! Some of the best roads in the UK :-) especially Hartside Pass.
I am interested in your reply re the first half of the journey as we will be travelling from Dalton in Furness to Penrith on a Friday afternoon in a couple of weeks and are planning to go over the Kirkstone Pass. I see we have two choices, either head up to Newby Bridge and pick up the A592 via Windermere or take the A593 through Coniston to Ambleside. My concern with the later is that I would then need to drive up the Struggle to pick up the Kirskstone Pass and I am not a very confident driver, however all the advice seems to be avoid Windermere if possible.
I wouldn't disagree with Ursa's suggestion - it's a great drive over the Alston Block, and a route I have driven when I have had plenty of time. There are so many lovely routes in this part of the world - by the way, there are really only three routes and five roads that cross the border into Scotland - the A7 or M6 at the Solway Firth, the A68 over the Cheviot, or the A1 or A697 along the east coast plain.
The main reason I didn't mention the possibility of travelling east and then northwest was that if OP decides to stop at some of those spots en route, they won't make it to Embra by 3pm!
To LittleMiss... The Kirkstone Pass is an impressive spot to drive through, but there's nothing particularly hairy about driving that road. The Struggle is the minor road that runs up from Ambleside, right? It's a bit narrow in places, I think. It's three or four years since I last drove it, but I don't remember it as being any different to the narrow minor roads around the Chinley, Chapel, Castleton area - if you've driven on those you will be OK on the Struggle.
The HardKnott Pass is for sure one that less experienced drivers to avoid - the hairpins near the top on the western side really are very steep, and all the approaches are narrow. But you are going nowhere near there.
But I don't know why you are being steered away from Windermere. It's a busy little town with a small one-way system, but almost any road in central Manchester is harder work and driving the A6 through Stockport is much harder (especially with the recent traffic works at the new Asda). More to the point, the A592 doesn't even go through Windermere! It does go through Bowness, and there is a somewhat busy junction in the centre with the A5074, but just turn left and continue along the lakeside following the A592.
Or you could go through Coniston and Ambleside and come back down the A591 to turn left onto the A592 on the north side of Windermere?
Thanks John thats a great help, I think avoid Windermere is the advice given because its so busy as opposed to difficult roads. I've never driven in Manchester, on the rare occasion I have to visit I use the tram and am lucky enough to work a few miles from home so don't drive much,however I am sure we will be fine, think Ive just read too many posts about the Lakeland Passes!!