Prior to 1855 family history becomes more of a challenge as the records become increasingly patchy and you will need to cast your net wider to find the information you are looking for.
Before Civil Registration became law, most records of baptisms, marriages, proclamations and burials were made in registers of the local Church of Scotland parish church. The Old Parochial Registers (OPRs) relating to Aberdeen & Aberdeenshire have been microfilmed and the main local libraries have copies of these films relating to the whole area, as does the Aberdeen & North-East Scotland Family History Society. All local Registration Offices also have access to digitised images of the OPRs as well as indexes for baptisms and marriages for Scotland. Digitised versions can be accessed online at www.scotlandspeople.gov.uk.The International Genealogical Index (IGI), available on microfiche, is also useful for helping to identify relevant records in the OPRs.
For deaths before 1855, again use the OPRs for the appropriate parish, however it is worth noting that death entries before 1855 give little or no genealogical information.
For the non-established Church denominations: Roman Catholics, Episcopalians, Protestant Non-Conformists (Free Church etc.), Society of Friends or Quakers, Baptists, Methodists, Congregationalists and Unitarians. Many of the records (and/or photocopies) are held at the National Archives of Scotland in Edinburgh although it is worth checking with Aberdeen City Archives and Aberdeen University as some of these records are held locally.