Genealogy research in early British Columbia records is difficult if not impossible, but there are resources available for everyone.
Firstly, anyone can go the the Hudson's Bay Archives website and download the biographical sheets for anyone they are interested in, if those biographical sheets are available. This will give you a short history of the person, and by following the file numbers on the right hand side of the sheet (by requesting the files from HBCA), you can see the actual record.
Secondly, anyone in Canada, and perhaps people outside Canada, can request the microfilm reel of the post they are interested in researching. Generally speaking, first access the HBCA website to find the number of the microfilm[s] you need. Then request the film at the Interlibrary Loan desk of your local library (main branch, probably). If the library does not deal with HBCA (and most do) you can find out from the Reference Desk who you need to go to to request a microfilm reel. Libraries generally provide readers for the microfilms, and you are only able to read the films in the library.
Account books for the various forts sometimes list employees at the fort and their dates of working, ages, and wages -- they are a valuable genealogical resource. But also look through the post journals and sometimes the outgoing correspondence, if the person is significant enough to be mentioned in those letters.
A second resource is the website for the British Columbia Metis, at www.bcmetis.ca. They have listings of post journals and other published and unpublished resources available in magazines and on the internet. Anyone can access the site for free, but you may have to register with them.
A third resource that I have not yet accessed -- for early baptismal records and some marriage records -- is the archives of Gonzaga University in Spokane, WA. Many missionary records are preserved there, and it is a resource that is not often mentioned. However, their records might also form the basis for the series of Catholic Church Records of the Pacific Northwest, so if your ancestors' records are not in those books, they may not be in the Gonzaga University records.
Good luck in your search.