As you already know the Suicide squad was built as a backup to do the dirty work which the main super heroes would not handle. They are controlled by the director Amanda Waller. They work in total secrecy until the Batman arrives and he does not like the way this team operates. It is against the ethics of these super heroes.
While these two teams are busy fighting each other the another super villain Maxwell Lord gathers a team of biggest villains in DC universe to take out both the teams. Some of the well known members of the Suicide Squad are Amanda Waller, Rick Flag Jr, Bronze Tiger, Captain Boomerang (George “Digger” Harkness), Count Vertigo, Deadshot, Joker, Doctor Light (Arthur Light)
This graphic novel collects the following comics Justice League Vs Suicide Squad issues #1-6, Justice League issues #12-13 and Suicide Squad issues #8-10