About these decks
N'Zoth Rogues are the most common form of N'Zoth decks, mainly because Rogues have a plethora of Deathrattle cards at their disposal, such as Xaril, Poisoned Mind, Undercity Huckster, and the new Deadly Fork, along with Journey Below. This allows for people to make this type of deck easier for Rogues, whose class is hard to make a good deck without at least two or three legendaries. N'Zoth Rogues focus on the synergies made through Deathrattles, and allows for buffs to be executed easier, along with damage.
How to make N'Zoth decks easier
Since most N'Zoth rogues have to have at least Cairne Bloodhoof or Sylvanas Windrunner in order to be a legitimate deck, those of you that don't have those cards may feel like you might want to dust N'Zoth. Don't do that. N'Zoth is still a good card, no matter what type of Deathrattle cards you have. Try to include several Taunt minions that have Deathrattle, like the listed Infested Tauren above, as it'll help you when you summon N'Zoth, guarding your face. There are many others that can help increase your minions' stats, like the Spawn of N'Zoth, which is wise for increasing the stats of your minions on the board, or the Anubisath Sentinel, who, after strong board clear like Flamestrike, can enhance a surviving minion's stats. Good luck with N'Zoth Rogues, and remember, they are probably both the easiest and cheapest way to create a slow, but good deck!
What you can add
If you're the kind that has more legendaries, probably add either Sylvanas or Cairne (if you have the dust) because you can take control of any minion and summon Baine twice in a row after summoning N'Zoth. However, if you're the kind that has these cards, probably transition to N'Zoth Pally, as they have few Deathrattles, but lots of removal and buffs. N'Zoth Rogues are mainly for the people that like quick games and fast opposition removal, while having N'Zoth and a lot of cheap Deathrattles at the same time.
The power of the Old Gods...combined!
If you have some fairly good C'Thun cultists, especially Blade of C'Thun, probably take some spells to add more cultists that can empower your C'Thun at a fast pace WHILE having N'Zoth at the same time. This can make sure to have a completely buffed behemoth on the board while having total board control through your resummoned Deathrattle minions. It's not like I completely recommend this, but if you have an idea how to implement BOTH Old Gods in there, then go do it.