The first and most important hints to find the origin of your ancestors can be found within your own family records or an elder relative's memories before turning to the internet. A professional researcher will help you find the clues in your possessions or memories, prompting the outline of any family and then continue to help fill in the colour of your ancestors’ lives. However, this is only the first step into your past and your ancestor's histories.
There are many databases and web pages which can be useful to investigate the origin of your ancestors. The internet provides you with initial information but with the coincidence of naming patterns, similar surnames or surnames that changed due to illiteracy can all lead to making the wrong conclusions about your family. A professional researcher will ask the right questions to determine which family ancestral path is the correct one to take.
There is a very wide range of sources which may be used in investigating one's family history and while there are a number available on the internet, some database subscriptions can be expensive to maintain; however, a professional researcher will maintain subscriptions with all the major databases and also a lot of the smaller, not so well known ones too that can be a treasure trove of supplemental information.
How far back I can follow the traces of your ancestors depends on different conditions and to which country our research applies.
Obviously, in Canada being a newer country as far as researching ancestors is concerned there are records for Ontario, Quebec and the Maritime Provinces back to the 18th century. The western provinces were developed later although there may be records in private archives such as the Hudson's Bay Company.
I always endeavour to go back as far as I can but much will depend on the records available. Also, if your surname is distinctive, that could be a help or a hinderance due to spelling assumptions when records were created. All it takes is another dialect that isn't heard correctly or a person unable to read or write and you can get many spelling variations.In the United Kingdom, we have the censuses available back to 1841 and civil registration began in 1837; however, many parish records are available at the various family history societies in England and Wales which could take us back a century or more. It is possible, depending on how extensive a search is requested, that a third party with access to the physical registers will be engaged but this will be set out in our estimation of fees.