So what is a tank? A tank is someone who can take a nice amount of damage, but also with all the armor/health he can do a nice amount of damage to cause the enemy team to think twice about ignoring the tank.. THAT is a tank!

Please note I do not know how to add little graphics and such, so I hope my guide is helpful enough without it.

So max your blade spin first, get 1 point in defense, at level 4 your silence, then your level 6 skills. After your blade spin is maxed, start your defense skill (W) because you will appear more deadly to them and you want to avoid being downed easily. If you are finding your getting downed easily in lane, max your (W) first because you are a tank after all.

Now why would I get these? Well my friend pointed out why, he refuses to make a guide so I do it in his place lol.

Marks: Greater mark of might, why? Why not! First off lets look at our options, there's health, armor pen and mark of might. You are most aggressive when in the enemy group spinning and hitting. Also your spin and hit does not stack with armor pen, so that's useless. Also you wont be just running around stabbing people, *hopefully* by the time your spin is done, your enemy team will be half dead.
So by getting mark of might, you are steadily increasing your damage every level.

Seal: Seal of Defense. Simple, Resilience does give you a nice amount of armor early game, but late game you will be falling behind on armor. With defense you get a nice amount of armor at level 18 without items, so this helps.

Glyphs: Glyph of Shielding. Magic resist, I know I know, you are low magic resist early game, but remember your a tank, you wont be trying to get kills, if u can great! But ur focus is farming and helping so stay away from those nasty AP nukers early game.

Quint of Swiftness: Why? Why not! Get outta there when your low, why feed an enemy team when ur team mates are full health and ur almost dead cuz they focus u, just run! and this will help you outrun them, or to chase that squishy down with your (R) and finish him quickly lol

Summoner spells:
Heal and Exhaust.. I know there could be other "better" spells, but that's for people who don't know what it means to be a tank, look further to find out how to play the tank Garen.

Heal: you support your group, you NEVER enter a battle by yourself, your team mates must always be around to help.. thus why heal is great if the enemy team does not focus you, you heal your team mate.

Exhaust: Great spell, wonderful spell, especially early game, amazing late game. Situation early game: You are laning with great dps, you spin on them dont do much dmg, but they decide to focus u because u are standing there taking a bunch of hits, your team mate is downing one of them, you are at 40% health u exhaust the one they are downing (or before to make sure they don't escape) and you get the hell out of there, you use heal if need be.
Late game: Exhaust their carry, get them to focus it, or better yet exhaust someone you lure into that bush with 5v1 LOL Over kill, but we wanna kill them.

Masteries:
9/21/0
Straight forward, exhaust improvement, a bit extra damage + armor pen
Improved Heal, armor and magic resist improvement, health imrpovement, and dmg reduction + cdr

Pretty Straight forward

Now we get to the meat and potatoes of Garen's build, all those items up there minus 3 items are situational!

First off dorans shield to begin with, health bonus, health regen and def
Then Mercury Treads (regular boots first then health belt THEN treads) then sunfire cape.
Then Agies, great benefits for your team. And finally Guardian Angel

Those are the MUST have items, sunfire is great to dmg enemy team even further and minions, mercury treads for more CC resist and magic resist.

Guardian Angel, why? Well by the time you get all the other items and build your GA, you will be VERY hard to kill (unless an enemy champion is fed) so if they are dumb and still decide to focus you, once you die, you will come back to life... very painful for them lol

Now situational items, you experienced LoL players should know why the situation items are as such. Ill give a short explanation

Raundins: It could be used against any team, and could be considered the next item to get regardless of the enemy team, but if you are facing heavy AP team force of nature of banshee might be useful. Thornmail is good for if you are fighting heavy AD team (gp/tryn/xin) etc, so if the game is going on this far in, look at how your enemy team is building, and build accordingly. But if no one is feeding, you should be relevatly hard to kill anyways lol

So you are a tank, remember that!

Even tho early to late game you are tough, you are not invincible, and if you run into a group of enemies, or chase someone to far, and get ganked by the enemy, your team could lose the game. You are VITAL to them with this build, you are AoE and do decent damage, don't get cocky/stupid/lazy and get ganked.

Early game: Try and farm, don't harass to much and try and keep the lane in the middle, don't push to far into their turret (especially if they have a jungler) your build is expensive, so farming is the best, if u are at least 99% sure u can get that kill, do it, but your focus is farming, not ganking so play safe.

Mid game: By now you should have sunfire cape, it will make farming SO Much easier, but ur not done yet, now you must be aware of your map a lot more, watch for pushes, call MIA, don't push turrets, let your minions do that, unless your absolutely sure that you won't be getting ganked by your enemy. Key to a successful tank Garen is farming, so remember that!

Late game: Stick with your teammates, keep an eye on baron. DO NOT initiate at turrets, and work with your team, luring them into a bush is a good idea, (such a BS tactic tho) but it works, when you attack, silence someone who has burst dmg first, pop your (W) then spin, by the time the spin is done, your silence should be back up. Your silence speed increase + your spin is a deadly combo for chasing those low health baddies with constant damage. It takes time to know how to play, but you won't feel inferior in damage while taking a lot of hits.

Remember: Call MIA's keep an eye on your map at all times! Make sure u direct your teammates as well, telling them to advance to retreat depending. Remember tho! You ARE a TANK, so do not go about by yourself or take on 2v1. basic points to know!

So I hope this guide gives a whole new understanding to Garen. I don't think I made any mistakes, or left anything out, but if I did please tell me. And don't just look at it and downvote, if you downvote tell me why. If u vote up, leave a comment, it's great to hear feed back.

Hope you summoners enjoy this build, and remember, leave comments! lol