I've heard a combined avoidance of around 40% is good. More is better. Less is not. (Unlike defense, where you pretty much MUST have the 540) Armor is also significant, and about 22k is "good". (Warrior, right?)
There's also hit, expertise, etc, to consider.
But Murdog's answer is the simplest. Get to 80. Run some heroics. Now you're ready.
Im just trying to dispell this shroud that ppl have made regarding "Minimums" to me its the stupidest thing adn yet there are prolly 20 threads on "Am i ready for Naxx?" people should just learn to think and use the knowledge that any ppl here are trying to give and not be hand held through everything.
I had full sunwell gear walking into Naxx25 all i did was throw Def gems in every slot to gain crit immunity and went on my way i had prolly 20K HP around and i had shit for avoidance due to the lvl 70 gear i was wearing. And so by the standards that supposed smart people put out i should have never went into naxx cause i was no where gear'd towards where i should be ..... Hmmm knocking it all out pretty much the first night, yea i don't think i was ready.
For the record im not trying to take shots at you Whitegold or Tezzi just trying to convey a msg that stat minimums are misleading and every question doesn't need its own thread just look at previous threads created compare gear and then make a judgment call usually if you have common sense the call you make will be the right one.
You have a point Murdog, minimums are not everything and skill level will determine if you can make do with less or need more in order to survive as a tank. However for beginning tanks it can be very hard to figure out what is needed or expected for tanking heroics and raids. Ask too many questions in gchat and people may start thinking you don't know what you're doing, ask too few and you may not learn some detail that is important. Also knowing that you meet certain minimums of surviability will help you keep your confidence when raid members start inspecting your gear and listing off things you "must get" and things you "must get rid of!" Having someone do a line-veto of your character is not fun even when they're trying to be helpful.
For tanks just starting out you need to be 535 for offtanking, 540 if you want the boss. A good 20k armor is required and over 20k health. Once there start stacking health until you get enough epics to allow for avoidence and threat generation. Most importantly watch videos and read guides to boss fights. Knowing the fight and your own gear deficiencies will let you warn healers when to pay close attention, and dps when they need to hold back or push harder. Hope you enjoy tanking Tezzi!
1st of all... im she not a he :P
I know how to gear up my self, i always aim for encants, gems all extra u can get etc. Much is your own sense, no need to read up about that. What i want is some kind of "line" that i/we officiers/gm could sow for our members, instead of whispering all u need that and that etc. Would be graet to show "this is minimum for u before u enter Naxx"
Get 540 defense is easy imo. But the rest? Atm when u check about gear to naxx, all says 540 defense. I got a healer lvl 80 aswell, and belive me itīs a HUGE difference to heal a tank with medium/high avoidance then one that got lower. And i just talking about heariocīs here to heal. Itīs not fun to spam spam spam heal.. When u know the difference. So im kinda talking about those minimum from both tanking and healing-wiew.
Well I would recommend the following things, Be Imba! - the online Character Auditor for World of Warcraft is still a good spot to go to see kind of where your members should do alright in instances, I use it weekly to check up on how my naxx group is shaping up. It helps me track their progress of gearing, I can see who also is not improving or doing their best to get geared. You should encourage all of your members to run heroics as much as they can to get both the gear and badges towards other gear as well.
It's difficult to draw a minimum line in the sand I rely heavy on be imba as well as running with my guildies in heroic to gauge how well they are performing prior to taking them into naxx. Another useful thing you can begin to use is combat log stats to see how people are performing in raid.
Just a couple tips for you, if you need anything else don't hesitate to ask.