Hello everyone, I'd like you to read this guide and only if really necessary downvote it.
This is a 'Breaking the Meta'-guide. This means it's not the usual way to build and play him. I got some good scores with it before. In every topic I will try to explain why to get this stuff.

Pro's + High sustain (through heal and high Armor) + Hard CC (stun) + Ult that buffs entire team

Con's - Your team complaining about your unusual build - Low mobility

Seals: for seals I chose Greater Seal of Armor because they give sustain in early game. This is a requirement for almost every jungler.

Marks: for marks I chose Greater Mark of Attack Speed. These are most useful I think, because your basic attacks will deal quite some damage.

Glyphs: for glyphs I chose for Greater Glyph of Mana. This will increase your damage further through Seraph's Embrace and your passive Gemcraft.

Quintessence: For quintessences I picked Greater Quintessence of Experience. I know they're not chosen often, but on Taric they're useful because he really needs his levels.

These are the runes I prefer but if you really want to take others, that's ok. I can't stop you, I'm not your mother.

: Smite is compulsory for every jungler! You have to take it to secure your buffs or steal enemy buffs.

: Flash is the usual summoner spell I take because it gives me the chance to escape from or catch up with enemies. If you really want, you can change this.

: If you really want you can change Flash for Exhaust

Ability explanation

Gemcraft: Taric's basic attacks deal 2% of your total Mana bonus magic damage; this bonus damage is doubled against champions.
This passive is why I came up with this build. With this build you have a lot of Mana which will increase the damage of your basic attacks by a considerable amount.

Imbue: Taric brings forth earthen energy to heal a target ally and himself 60 / 100 / 140 / 180 / 220 (+60% of your total Ability Power). If he targets himself, the heal increases by 40% restoring 84 / 140 / 196 / 252 / 308 (+84% of your total Ability Power) health.
This is a very useful skill because you can heal yourself when your in the jungle. So you can stay longer in the jungle and gank more without having to return to base.

Shatter: Passive: Taric's gemstones increase the Armor of nearby allied champions by 12% of your total Armor. Taric gains an additional 10 / 15 / 20 / 25 / 30 Armor for himself. Active: Taric shatters his armor, dealing 50 / 90 / 130 / 170 / 210 (+60% of your total Ability Power) (+20% of your total Armor) magic damage to nearby enemies and reducing their Armor by 10 / 15 / 20 / 25 / 30 for 4 seconds. Taric loses his personal bonus armor while Shatter is on cooldown.
This is a nice ability for a jungler because all the neutral monsters in the jungle (expect Baron Nashor) deal physical damage. This gives you a nice amount of sustain.

Dazzle: Taric fires a prismatic sphere at a target enemy, stunning them for 1.2 / 1.3 / 1.4 / 1.5 / 1.6 seconds and dealing between 40 / 70 / 100 / 130 / 160 (+40% of your total Ability Power) and 80 / 140 / 200 / 260 / 320 (+80% of your total Ability Power) magic damage. Dazzle's damage increases the closer Taric is to the target.
This skill is nice when you're ganking. Just stun the enemy and kill him.

Radiance: Taric slams his hammer into the ground, dealing 150 / 250 / 350 (+70% of your total Ability Power) magic damage to nearby enemies. For the next 10 seconds, Taric's gems radiate energy, granting him 30 / 50 / 70 Attack Damage and Ability Power and his nearby allies half of the bonuses.
This is Taric's ult. He deals a nice amount of damage at the activation of it gives your allies and yourself a high increase in damage in teamfights.

Ability Sequence Order
I recommend starting with Imbue so you can heal the damage that the blue buff monter dealt. After that I recommend taking Shatter to increase your survivability even further. After that you can max whatever you want first. A point in your ult has to be taken whenever possible of course.

Here comes the biggest 'Breaking the Meta' part. I recommend reading all of it and try to figure out a build that suits you.

Muramana: An item I really like on Taric. It gives a lot of Mana which increases the damage from your passive Gemcraft and if toggled on, your basic attacks and Dazzle will deal increased damage.

Iceborn Gauntlet: Also one of my favorite items on Taric. It gives a little bit of Ability Power, quite some Mana and a lot of Armor (which will be increased through Shatter). Also it's unique passive Spellblade is very useful.

Rod of Ages: Agian an item with a lot of Mana and a lot of Health. It also provides some Ability Power which is never a bad thing.

Seraph's Embrace: The equivalent of Muramana but with Ability Power. It synergizes very well with Muramana.

Trinity Force: An item with a lot of nice stats: Health, Mana, Attack Damage, Ability Power and Attack Speed. Also with a unique passive Spellblade, so choose between this or Iceborn Gauntlet.

Blade of the Ruined King: This item i usually take for it's passive, Attack Speed, Lifesteal and Attack Damage. It's a very nice jungle item.

Berserker's Greaves: For second tier boots I recommend these. They provide a good amount of Attack Speed which is needed in this build.

Guardian Angel: This item gives nice defensive stats and is known for it's passive. I take this item if the enemy team has a lot of AD and a lot of AP.

Sunfire Aegis: This item gives youHealth and Armor, that's always welcome. And it increases your damage through it's passive. This item will increase your jungle clear speed a lot.

Spirit Visage: If you're in desperate need of Magic Resistance I would take this item because it increases the amount of Health that you restore to yourself with Imbue.

Nashor's Tooth: Useful for it's Attack Speed and it's Ability Power. Also it's passive is nice because Taric deals damage with his basic attacks but he also has some Ability Power.

Early game: In early game I usually don't gank very often. Only if a lane really needs it or of I see a perfect opportunity I will gank.

Mid game: When I have my second core item, my clear speed increases significantly, so now I will start ganking more and try to counter-jungle more.

Late game: When teamfight happen more and more, you always have to be there. Your Shatter and Radiance will help your entire team and help you win the fights so you can push lanes.

I hope you read my guide and you will comment with help or questions. If you downvote anyway I'd like to know why. And hope you liked this ans I wsh you good luck.