! have used this firm for over 20 years but these days the same product is available on ebay and they are around £5-£6 each, excellent value and of course they are OS 1inch to 1 mile maps which give great detail for family historians and there is the 1909 series too which works well with the 1911 census. you can usually identify churches and schools and possible work places which is what we need to be looking for as most people walked to work or school unless they were in a large city. as for online, you can get tasters like the previous reply mentions but it's not the same as being able to own the map and highlight the important bits yourself! plus you can scan them into your pc and upload the detailed areas onto ancestry or similar sites where you keep your online tree.
http://www.alangodfreymaps.co.uk/