Here are some online maps that I've found useful. The titles in the links are not particularly useful, but when you follow the link you'll see what you get. I but them in order of age, with the first picture map being the exception. If you look through these you'll notice that some of them borrow from others. Whether it was plagiarism or authorized I don't know. You may also notice that the early maps are not perfect - the streets are represented, but not exactly following the correct paths. I think we have to be careful about relying too much on these documents for accuracy. They tell us a good deal, but we can't be sure that they get everything right.
The later ward maps were made for the fire insurance industry, and give every building and the owner of each - very cool.
Bird's Eye View - 1891
Boston and its vicinity - 1819
Map of Boston and its vicinity - 1829
Map of Boston and its vicinity - 1858
Map of Boston - 1860
Map of the city of Boston - 1866
Boston and its environs - 1867
Map of Boston - 1867
Map of the city of Boston - 1867
Map of Boston and the country adjacent - 1874
Boston - 1888
Boston sheet, Geological Survey - 1890
Wards 19, 22, Bromley Park - 1895
Wards 19, 22, Hyde Square-Heath - 1895
Ward 22, Amory street - 1895
West Roxbury, Dorchester, Brighton - 1899
Ward 23, south of Forest Hills - 1899
Wards 22, 23, north Jamaica Plain - 1899
Ward 23, Forest Hills & Arboretum - 1899
Wards 22, 23, south Jamaica Plain & Forest Hills
Boston and surroundings - 1927
And don't forget the map page on the Jamaica Plain Historical Society web site. They were able to take pictures of fire insurance maps that are not available online.