WHERE TO STAY: Mainland, Orkney, is a fairly small island, so it's a good idea to go there slightly out of season and make reservations. Elsewhere on the mainland of Scotland you can pretty well get into a hotel or inn near the places I've mentioned. If you're not staying within five minutes of a site, you'll certainly enjoy the trip there and back.

Here are some of the better places to stay:

Kirkwall, Orkney Islands: Good hotels in or near Kirkwall include the Kirkwall Hotel, the Lynnfield Hotel and the Foveran Hotel.

Dingwall: The Royal Hotel is modest but good.

Strathpeffer: The Strathpeffer Hotel is large but reasonable.

Inverness: Two traditional are the Caledonian and Station. Wonderful Scottish breakfasts.

Torlundy, by Fort William: At the other end of the Great Glen from Inverness, an ex-millionaire's castle with out-of-this-world comfort and food, and prices to match.

Aberdeen: Holiday Inns, of course. (Aberdeen is an American city now, because of North Sea Oil. Well, almost.) Nearby at Old Meldrum is Meldrum House Hotel, whose distinguished owner is a gourmet cook.

Stirling area: Golden Lion Hotel, Stirling (for food), Airth Castle Hotel (a castle in its own grounds) for food and residence.

Loch Tay: The Kenmore Hotel (great for fishing) claims to be the oldest inn in Scotland. The inn at Fortingall nearby doesn't boast the same age, but the yew tree beside it is said to be 3,000 years old, and Fortingall itself claims to be the birthplace of Pontius Pilate. Brood over that as you eat your fresh-caught salmon.

Perth: Two traditional hotels are Salutation and George.

Pitlochry: Fisher's Hotel, Atholl Palace Hotel, Pitlochry Hydro, among dozens of good ones.

Fife: Old Course Hotel or Rufflets, St. Andrews. The famous Peat Inn, halfway between St. Andrews and Earlsferry, for food. But book beforehand.

Edinburgh: Anything goes. There's even a Sheraton now. The traditional hotels are the Caledonian, the North British and the George. Good food with stately surroundings at the 17th-century Prestonfield House and at Houston House, a restored ancient keep at Uphall a few miles away. Or Georgette Heyer fans might like to try her gracious-living residential hideout 40 minutes south of Edinburgh, Greywalls Hotel, Gullane, beside the beach and the famous Muirfield championship golf course.

GUIDEBOOKS: The bookseller James Thin, South Bridge, Edinburgh, carries huge stocks of Scottish guides and background books, and has sister shops (called Melven's) in Perth and Inverness. There you can get either of the two versions of the Orkneyinga Saga, and books like "The Moray Book," "The Caithness Book" and "The Hub of the Highlands," about Inverness.

Aberdeen writer Cuthbert Graham has published two very good topographical books on the Moray Firth, and on Aberdeen and Deeside.

In 1981 Sphere published an excellent book called "Scottish Island Hopping" by Jemima Tindall, and there are at least two first-class guides to the Orkney Islands, plus a whole series of detailed guides on Birsay and on all the monuments in government care, which H.M. Stationery Office in Edinburgh can tell you about.

Good guides to prehistoric Scotland include the one by Richard Feachem, published by Batsford. And wherever I go, I always buy the Blue Guide, published by Ernest Benn Ltd. The one for the whole of Scotland is indispensable. Look out, too, for the Arden edition of Shakespeare's "Macbeth," published in paperback by Methuen, which pays special attention to Shakespeare's source Holinshed, but doesn't have space to show how Holinshed came to make his mistakes.

And for those seriously interested in Scottish history from prehistoric times to the 13th century, read volume one of the Edinburgh History of Scotland, "The Making of the Kingdom," by A.A.M. Duncan.

Ordnance survey maps of Scotland are fantastically good and come in every scale you can think of: Every big bookshop in Edinburgh carries them. The Royal Automobile Club also covers Scotland in two excellent road maps at four miles to the inch. And if you really get hooked on Orkney, Pedersens Highland Maps do a map of Orkney and Caithness with all the places marked with their saga names.

Lastly, there is, of course, fiction and historical reconstruction. My own novel is called "King Hereafter" and is published in hardcover in Britain by Michael Joseph (Knopf in New York) and in paperback by Hamlyn (Britain only).

Books on Macbeth of much interest, but for which I can hold no historical brief: "Murder Under Trust," by Arthur Melville Clark, and "Macbeth," by Peter Berresford Ellis. For romance, try "Macbeth the King," by Nigel Tranter. -- Dorothy Dunnett