You will have no problem getting to the Scottish Highlands. You can fly to Inverness , which is just about an hour and a half from London. There are daily services between Inverness and London Gatwick and London Luton with EasyJet. British Airways route from Heathrow starts in May 2016.You can also fly to Inverness from some other places including Birmingham, Bristol, Manchester, Dublin, Belfast, Amsterdam, Shetland, Orkney, or the Western Isles.  Inverness Airport is about seven miles east of the city and there is a good bus service departing every half hour during the day; taxis are also available.

Inverness has rail connections from Edinburgh, Glasgow and Aberdeen and lines continue west to Kyle of Lochalsh (for Skye) and north to Wick and Thurso.  There are also two services a day from London, an East Coast service from King's Cross and an overnight Caledonian Sleeper service from Euston; the sleeper doesn't run on Saturday nights.  You can also travel by Caledonian Sleeper from London to Fort William, then on by train to Mallaig on the west coast, from where you can catcha ferry to Skye.  Look out for special fares, particularly the 'Bargain Berth' scheme which has limited availability of sleeper berths (in 2-berth cabins) from £19.  These can only be booked online via the First Scotrail website and the lowest-price berths disappear very quickly.  The rail journeys from Inverness to Kyle of Lochalsh and from Fort William to Mallaig are among the most beautiful in the world and are worth doing for their own sake.

There are bus services to Inverness from Glasgow, Edinburgh, London and intermediate points; there is also a service from Aberdeen. 

If you want to drive to the Highlands, you can take the A82 (Glasgow-Fort William-Inverness), the A9 (Stirling-Perth-Inverness-Thurso), or the A96 (Aberdeen-Nairn-Inverness). If you are travelling from the south of Scotland the A9 is a much faster route than the A82, with some dual carriageway; allow about three hours from Edinburgh to Inverness and about half an hour more from Glasgow. It will take you the better part of five hours from Glasgow to Inverness on the A82, though that road does pass through some wonderful scenery (such as Rannoch Moor, Glen Coe and the Great Glen, including Loch Ness) so you might want to consider it for a leisurely outward or return leg.  Most main roads in the Highlands are two-lane single carriageways but in some remote areas there is only a single lane road with passing places.Generally, surfaces and signposting are good.

 If you want to travel to the western or northern isles, there are FlyBe services (operated by Loganair, with a British Airways codeshare) connecting Edinburgh, Glasgow and Inverness to Barra (Western Isles - the plane lands on the beach), Stornoway (Western Isles), Kirkwall (Orkney) and Sumburgh (Shetland).  There are also flights to Shetland and Orkney from Aberdeen.  Ferries to the Western Isles and inner Hebrides are operated mainly by Caledonian MacBrayne and depart from various ports on the west coast. 

 Ferries to Orkney operated by NorthLink Ferries depart from either Scrabster, near Thurso (which sail to Stromness in Orkney, two or three times daily), or Aberdeen (which sail to Kirkwall), three or four times a week.  There are also several daily services from Gill's Bay (near John o'Groats) to St Margaret's Hope in Orkney, operated by Pentland Ferries.  Ferries to Shetland are operated by NorthLink Ferries and depart nightly from Aberdeen, sailing overnight, and some call at Orkney en route.