Here we have this is Slater's Directory of GLASGOW in the year 1903 on CD ROM
It lists Private Residents, Trades People and also offers plenty of information concerning the infrastructures of the towns and villages in this period. Please note they don't just list the elite this is a common misconception.
There are plenty of people of average standing in the community, such as Butchers, Joiners, Shopkeepers, Boot & Shoe Makers etc However even if you know for certain that a relative was living in a particular place at a certain time it does not automactically follow that you will find them in a book as it was the individuals choice as to whether they went into these type of publications, but it's great fun looking & you might get lucky !