I really can't think of much from other books that would be needed for Lockdown.
I do suggest getting a map of Boston, be it paper or a stored digital one, that you can mark up with locations and territories. There is enough of an element of dealing with gangs and neighborhoods trying to hold on and so forth that the sense of geography is good, I think.
Before you get into it, I'd put some thought towards how you intend things to end. By books-as-written, by the time they get through the written adventures there is not getting out of the city for a few years. If they survive the ending in a way that leaves them at liberty, do you just end the campaign there? Do you keep running in locked down Boston? Let them go through a bunkering up for the long run, and pick it up a few years later? Open an escape hatch for them? (I dropped Lockdown into an existing game, and didn't want to keep running there, so I opened an escape hatch for the characters -- but I'd set that up well ahead of time)