Ok my plan may seem like a bit of a rip off, but I have to go with it because it is by far the best one that I have ever read about. If you have read the series 'The Walking Dead' then you know what I will be talking about here.
My plan is to gather as many survivors as I can and get them to a safe place, a house, a camp in the open with good visibility all around. After that can be done, then I will form a scouting party of a few able bodied men to gather as many weapons and supplies as can be gathered from any nearby small town or settlement to sustain the others until the next phase can be completed.
The next phase will consist of another small scouting party venturing out looking for a well built and semi-isolated county detention facility or small prison(federal or otherwise). The reason for going with this instead of some rinky dink city jail or county jail is the defenses that are already in place i.e., walls(inner and outer), fences(there are usually multiple fences running paralel to each other around the facilities), towers(for look outs and watch duties), and all of the medical and food cooking facilities that you would need for a small populace of people. Through meticulous and methodical means, the prison, at least a good portion of it, can be cleared by just a few people of any and all remaining Zeds. Once that is found by the scouting party, the prison buses, if still intact and driveable, can be used to collect up the survivors left behind at the safehouse.
Once everyone is back within the confines of the very defensible area, the scouting party(members can be switched out/replaced at any time necessary) can then venture out once again, this time looking for the nearest military fort or base. The reasons for this should be obvious at this point, for the prospect of weapons, amunition, vehicles, fuel, rations, and any other supplies that can be loaded up onto the vehicles. Once the fort or base is located and properly canvassed, whatever supplies and etc can be gathered are gathered, they can then be transported back to the prison to be handled by the remaining survivors(who by this time should have been given duties around the place to make things run smoothly).
Next part is pretty much just repetition, going and looking for more survivors or supplies from anywhere and everywhere you can think of until help arrives or you are the only population left.
the things is there gonna be pretty ugh... "pants antsy being coopup in there for so long if i wanted to be a raider you know the dark side of the survivors comunity,i would go to jails to gather gang members i would say yo you wanna join my crew , every women is shared but i dont think you guys will give a shit about sloppy fucking seconds am i right?! i would be more afraid of humans then zombies.
you're right I've also visited an maximum security jail and it is easily one of the most defended structures in todays society, even with all the camera and think doors with the heavy locks there were also two rows of electrified chain link fences with motion sensors between them. When I toured it with my class they motion alarm went off because a rabbit had burrowed under