Useful Sources
Scotland is well served by many, many on-line sites full of information.
The Scottish Genealogical Society has a comprehensive list carefully categorised at
https://www.scottishgenealogy.uk/databases.html#/ It is a difficult thing to keep current!
This list is some of the generally applicable sources that I have found useful. No, I don't get kick-backs, unhappily.
1: Scotland's People: https://www.scotlandspeople.gov.uk/
Statutory records, Old Parish Registers, Church session minutes, censuses, glossaries of old terminology. Many less complete or useful compilations as well. Good research guides.
2: Historical maps:
https://maps.nls.uk/
Many, many maps and plans. Some features are hard to use: read the Research Guides first. Very comprehensive.
https://www.scottish-places.info/
A gazetteer whith lots of information - keep looking!
The Ordnance Survey books, which list every placename, farr name, well, church,house and dyke in the country as of iod 1800s. Now kept by SP:
https://www.scotlandspeople.gov.uk/virtual-volumes/os-name-books-main
If I find a place - maybe in a church record - this is the first place I lookfor details.
3: The Scots language: Dictionaries: https://dsl.ac.uk/ There are two Dictionaries of the Scots Language: pre 1700 (older Scots) and later (modern Scots). Easy to use.
The Scots Language Centre: https://www.scotslanguage.com/ Everything from recorded samples of accents to politics. Many an evening has been spent here!
4: Scottish Indexes: https://www.scottishindexes.com Husband and wife couple, Graham and Emma Maxwell, who have accumulated a mass of indices to less common records - health, justice and others. If you find something in the indices that is of interest, the whole record is usually available to buy quite cheaply. They also host free on-line conferences with a wide variety of speakers. Nicer people would hard to find. Ancestry is now indexing some of these.
5: The Scottish Genealogy Society:https://www.scotsgenealogy.com Lots of material here, although not always easy to find. Much is paid, rather than free. The index to their magazine The Scottish Genealogist is free to search, and relevant articles and back-copies can be bought quite cheaply.
6: Family Search: https://www.familysearch.org/ Lots of transcriptions, and many datasets not found anywhere else. Don't trust any user-supplied "facts" in the family tree - verify everything, since not everyone using Family Search can tell truth from optimistic guess-work. The Research Wiki is immensely useful.
7: Wills and Estates:
The source I have found most useful is the Ancestry Database of Confirmations (in England these are called Probate): https://www.ancestry.com/corporate/blog/exploring-the-scottish-calendar-of-confirmations/
Scotland's People has records of some larger estates, if your ancestors were better off than mine:
https://www.scotlandspeople.gov.uk/article/our-records-inventories-estates
8: Emigration:
Usually emigration records are just passenger lists with very few details, so it's hard to be sure that you have found the right person and not just someone with a similar name. Find My Past, Ancestry, Family Search all have various lists - and they overlap.
9: Cemetery Records:
Many councils have given the task of making cemetery records available to one of the commercial sites.
Angus: all the council records are on https://www.deceasedonline.com/
Aberdeen: https://www.northeastscotlandroots.com/useful-links/ has pointers to many sources
Banff: Find A Grave is useful; there are bits of records all over.
Kincardine: The Family Search Wiki has pointers to most of the churchyards in Kincardine.
Find A Grave https://www.findagrave.com/ has records for several Scottish cemeteries contributed by users, so not systematic. Billion Graves https://billiongraves.com/ has very few of the cemeteries I have looked for, and they appear to be incomplete.
Family History societies have often compiled booklets of the Monumental Inscriptions in cemeteries or parishes. There's a good list of them at
https://www.findmypast.co.uk/articles/aberdeenshire-banffshire-and-kincardineshire-monumental-inscriptions-parishes and a search engine is linked therefrom.
The booklets themselves are usually purchased (cheaply) as printed or digital copies from the relevant society's website.
10: Family History Societies:
Being about as far from NE Scotland as possible, I've found only a little use for the family history societies active in Scotland. Their publications and databases are sometimes useful, but look carefully before spending your bawbees on a subscription.
The Aberdeenshire and North East Scotland Family History Society http://www.anesfhs.org.uk/ covers most of the area of interest.
Angus is covered by the Tay Valley FHS: https://tayvalleyfhs.org.uk/
Other societies are to be found at the Scottish Association of Family History Societies
https://www.safhs.org.uk/