Welcome to my first build! Now that I'm level 20 I decided to make a build for my tank Garen or ad carry Garen. Note that this is how I play Garen and that you probably will end up having your own opinion of how you should build or you may just have another play style.

The pros and cons of Garen. (Do note that the more I play the more I will add to this page.)

Pros
+ Easy for newcomers.
+ Can solo lane like a boss.
+ A perfect tank for the team.
+ Almost better than Master Yi at harass.
+ Great farming with judgement
+ Has high armor and magic res
Cons
- Kinda sluggish.
- Cant out rank some of the other tanks.
- Very easy to kite.
- Is not an effective jungler. (why would you do jungle garen anyway?)

Farming is fairly simple as Garen, Just activate your Judgment and spin the minions to death.

These are the best items I can think of in my messed up head!
Ordinary build items

The black cleaver
The black cleaver is a great weapon for ad Garen and tank Garen, I took this instead of spirit visage because if you upgrade your Aegis of the Legion to a Runic Bulwark you will have enough magic res already.
Frozen mallet

You want this for your slow, Get it early game, so you can slow your enemy's for extra kills.
Randuins omen

This is a great item for tank Garen, and its active has saved me on occasion, But I would rather have this late then mid game because the runic bulwark gives me extra magic res.
The runic bulwark

I get this mid game due to extra magic resist and its aura for teammates.
Mercury's treads

Mercury's treads are great against high cc/slow teams and the extra magic resist helps against high ap teams. Don't take these against high ad teams unless its also high cc.
Infinity edge

This is for extra damage late game. You can switch this out for another item because its really only for the extra damage.

Situational items

Ninja tabi

Use this against high ad teams with not many slows.

Sight stone

If garen has to ward/Is the support then take a sight stone. (preferably a ruby sight stone)

Warmogs armor

You can take this in place of the infinity edge for more tanking but less damage output. The main reason I left this out is because warmogs are only giving you health, Not the armor magic resist or damage. If you leave out the damage your going to kill less people late game. (Wow this was a long explanation)

Atma's impaler

Couple this with warmogs for a higher damage output but less MR.

More coming soon!

As garen you should initiate team fights if you don't have a better qualified champion to do so. Try not to ks too much even know its hard to not ks as garen. As garen focus the highest damaging character with the lowest health (Ie. Teemo Master Yi Lee Sin etc.) or focus the support. (Ie. Soraka Sona Kayle etc.)If your teammates are really low or are just getting crushed you need to be the tank unless you have a better qualified tank with you. As ad garen just focus the same way you focus as normal garen, And remember: SPIN TO WIN!

Read the above :P

Thanks for reading my build, And all the support for the build! I'm aiming for the top 5 of garen builds, Once again thank you and there's more on the way!