Well I like to keep this short. GAREN= SOLO TOP. PS buy ward every time your back to buy item.
My Garen: The Armor and MR are not counted the Courage skill bonus that it farms up MR and Amor yet.
Amor: 112
MR: 90
ATTK: 241
Movement Speed: 457
Crit Chance: 88% which is OP for Garen spin, Judgement skill.
Cooldown Reduction: 15%

For Mark i like to use amor pen or extra power and zeal as hp regen cuz i like my Garen to stay long enough to harass and farm, but last hit creep only. For Glyph i grab magic resist in-case i get ganked by mid caster cuz top usually lane with AD and if i got hp regen for AD I'm good to go. Then i grab Quintessence rune of swiftness for extra movement speed so that i only need to buy
boot of speed which have movement speed enhance of 1 and still be able to lane due to my Q skill, which give extra movement speed when use it. Q skill have nice movement speed to harass and gain distance over the enemy and the quintessence of swiftness allow me to get merc tread and still have about the same speed movement as boot of swiftness. So I'm getting some nice magic resist and tenacity. I did not go quintessence of Fortitude which 26 hp each which is 78 hp total, i figure its not that big of a deal, as long as you last hit creep, do what you suppose to do, keep doing harasses then your good. It ONLY MATTERS THE PLAYING STYLLE, so don't complain of having 78 hp less because you can't dodge harasses.

For mastery i like to use 21/6/3. 21 offense to give me the power great for Garen's spin and 6 in defensive to get some great amor and magic resist due to my zeal runes are hp regen. I went 3 on utility becuz perseverence give me 4% hp regen which i totally loved it. With the build i have i start out with 21 hp regen so its totally awesome.

For starter i like to start with doran blade which gives 100hp and 10 attk which is so nice. I especially like to rush for infinity edge becuz of its passive 250% crit dmg and 25% crit chance and if you read your judgement skill carefully it said you get bonus dmg from the crit that you can from your spins. 250% crit dmg to it is awesome then i rush the impaler for the same reason and also some amor to tank tower and the impaler is give you the nice passive of 2% hp is being convert to AD dmg and with the hp you have right now will convert you like 52 AD which is better then a BF sword. I then rush a phage for the slow effect and some hp for impaler, but trust me after you got an infinity edge, your auto attk is fearful to squishy not to mention you now got a phage for slow effect. I then now like to rush for a warmog and if they got too much AP Nuker you can get Force of Nature for nice running speed and hp regen also don't forget the 76 magic resist. I like to to finish my build with finishing my phage to a frozen mallet and a phantom dancer for more crit chance. crit chance= OP Garen spin and by now you probably could feel it, your running like a horse, just on two feet and not 4.

For skill i like to max out my spin 1st which is your main dmg, i like to keep the W skill at lv 1 for it's passive to gain some resist and amor but also for farming becuz harasser will try to stop me from farming. I would need to last hit lots of creep and if i have to dive in and spam Q on tower to get a sing creep score i will and that is why i need my shield to atleast lv 1. Make sure you gotta know when to use the shield or else it's a waste of time and skill and it makes you look pro. look pro= look more sexy. P.S always estimate enemy hp b4 ulting them and always save your ult until enemy hp is low and your guarantee to score a skill then use it. Read your skill cuz im not gonna read it to you. Also it's better not to try to harass enemy until they approach to last hit creep, make them know whose boss.

I like my summoner skill to be exhaust and flash. exhaust and flash can be use for defensive or offensive so use your imagination.

I like to say any champ can be OP if you know how to play and play safe of course their are alot of countering champ but Garen is one of those i found have no weakness in soloing 1v1. Infact i don't ever remember losing to 1v1 top solo lane.

Don't even try,....... I know you're AD Garen, but still your teamate gonna need to jungle creep to catch up exp and gold. Since you're already soloing top, don't be greedy.NO ONE JUNG BETTER THEN THE BEAR!!!

You're are Garen use your shield to initiate, charge in with a silence on an AP nuker like Annie and exhaust 1 AD carry that you think is a threat, perhaps they have stun to counter your AP Nuker.

Last hit creep only and buy at least 1 or 2 ward when you basing. Use Q to smash a creep when you think last hitting gonna lose you 1 creep cuz it too far and you can reach it. Judgement can be use for countering your oponent's farming especially close range AD like Irelia and Akali which Akali is AP so every time you see they try to last hitting your creep, try and stand near it. If they last hit it anyways, but hey your close to enough to use your judgement and then end up with a Q on their head. Trust me, they can't get away from that combo especially when your Q give extra movement speed temporary.YEAH!!!! HUNT TEEMO!!!