I choose the masteries hypothetically because I am not level thirty but these are what I would choose. The runes are also hypothetical because I do not have a rune set for volibear yet but am working on getting one. The items where all planed out though.

I get the boots so that I have a better chance of getting out of tough spots right away and then the belt on my first trip because by level six i am to squishy to be a valid tank. After making my self less squishy I need to have the speed to chase down and kill weak enemies and to get away from strong ones. After finishing my warmogs which just helps to be a tank i get either the chain vest if they are doing lots of physical damage or the negatron cloak if their are doing more magic damage. Either way after getting the item i immediately go for the force of nature because its magic resist is greater than the negatron cloak where as the chain vest is only as good at atmas impaler. But do to the added attack damage for extra health the impaler is a no brainer for this build. After you have these four items you will probably be a very high level and again seem a little to squishy for a tank so what better to get than another warmogs. The added extra health will also increase the damage you are outputting making you a force to be reckoned with when you use your ultimate. When you are done with all those items if you haven't won yet and still have money the next choice will help you to survive not because of armour or magic resistance but regeneration. The spirit vassage seems like a bad item but when you have two warmogs and a force of nature giving you bonus health regeneration having the spirit vassage really helps. An extra fifteen percent health regeneration of your current health regeneration is allot when you start with allot and the extra cool down reduction and health are just little extra presents. If you find your self in a battle full build against a strong opponent you still wont die quickly because you are gaining it back unlike spell vamp and life steal in which you have to hit you are enemy you will keep regenerating even out of battle. If you find yourself with all this health regeneration and still getting close to dieing you will have an extra couple of seconds due to your passive which will most likely allow you to get the kill and have life remaining. Always remember if it is not going in your favor you will most likely be able to out run your enemy and will be gaining large portions of health at the same time keeping you on the front lines longer and being able to help your team out more.

first thing you should do is get boots of speed to increase your survivability. You should be able to stay in TOP lane until you are level six and you have enough to go buy a giants belt. During your first stay on top work with the minions until you and your ad carry partner are level two then pick their ad carry when s/he is away from the turret and destroy him/her. If you have trouble staying in lane in the beginning I suggest buying some health pots right away when you get your boots. If you are struggling to survive and find yourself under leveled Volibear is a good jungle and you will be able to make up the level difference quickly. If you continue to struggle then maybe you should be more conservative because I do not play a tank quiet right I've been told but this is a good build if you want to be able to stay in danger, take hits, recover quickly, and do damage all at the same time.