Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Really this is a build that is probably already out there but I thought I'd post it anyway. Just a tank build that works pretty well. Nothing too special but it works for me and hopefully it will work for you.
Start with Doran's Shield for the early game HP Regen then get Heart of Gold for the defense and gold per second. Then go for Mercury's Treads because Garen is rather slow without them. After that go straight for Sunfire Cape, start with Ruby Crystal for the HP then go from there. While building the other items try going for the HP increasing items in the build first. After you build Thorn Mail sell your Doran's Shield to get Guardian Angel. If the game lasts long enough go for Randuin's Omen. That completes the item builds.
Decisive Strike usually isn't the first skill of choice for Garen but i found that silence early game can help. Nothing else special here after level 3 start focusing on Judgment after that is maxed go for Decisive Strike then go for Courage. I don't train Courage first because even at level 1 it still helps, though if the situation calls for it you can max that instead of Decisive Strike or Judgment.
I usually take Ignite and Ghost. ghost helps you get away and ignite for killing the person trying to escape, nothing special here.
Pros / Cons
Pros - Good against teams that are focusing on AP.
Nice health mid and late game.
Still a good attacker even while tanking.
Cons - Bad against teams that focus on magic damage.
Rather slow at getting away if ghost is still on cooldown though Decisive Strike can help.
If you don't get gold quickly this build can be hard to do leaving you rather squishy.
Really a basic Armor Tank Build nothing special but 3600 HP + Courage is really nice while diving or while getting ganked but really is nothing special. there are definitely better builds out there but hey, this is my first build and it works for me so i thought I'd share it with everyone.