Here is historical information about the Jewish quarter, street by street
This is the route through the Jewish Quarter, in English
It doesn't take very long and it's nice to wander with an objective if those two things are compatible.
The 'Interpretation Centre' or very small museum of the Jewish Quarter, is in my experience either closed or without any illuminating information in English. This might have changed recently as i admit having given up going and there is certainly more information on the net than ever before. I got completely fed up with the archeologist's drawings of what they'd found, which were usually upside down when compared to the ground plan or in some way or other incomprehensible to the lay person. Especially the non-catalan lay person, who doesn't lunch for 3 hours.... It's here anyway - Placeta de Manuel Ribé. 08002 Barcelona
The History of the City Museum is fantastic however.
If the Jewish Quarters of the region are of interest to you, don't neglect to visit the Girona 'Call' and the 'Call' of Besalu, which has a very rare medieval Mikvé or Jewish bath, one of only 2 in Europe i believe. It was found by accident in the 60's and is in excellent condition.