Taric is not one of the more popular or straight up powerful champions in the League of Legends, however he can be played quite effectively as an all around mix. His extreme burst damage, stun, and heal capabilities make him the perfect puzzle piece for almost any situation.

The best thing to start with would be the fact that if you play well early game, Levels 9-14 Taric can easily solo kill most champions with the famous Stun->Radiance->Shatter combo. I personally have instantly killed some of the squishier champions such as Teemo or Karthas with the initial burst. Eventually however Taric will be outclassed by pure damage champions and it is best to switch to a simple stun, buff, and heal play style. Healing your teammates as well as using Shatter and Radiance to its greatest effect along with a well placed stun can make or break a game against any team.

First thing you are going to want to do for beginning game play is acquire ability power. I went with 9 Glyphs of Potency (AP) and 3 Quintessences of Potency for a flat 24 starting AP. This increases both your heal strength and your stun/shatter damage and should always be taken.
For Seals I chose 9 Seal of Replenishment (mp/5) as in begin game Taric is incredibly mana starved. For Marks I chose 9 Mark of Alacrity for attack speed, Taric's special ability gives him mana for damage his auto attacks do while also reducing his heal cooldown significantly for each hit.

The most important part! I start off with the Regrowth Pendant rather than the fairie charm for several reasons, 1. Clarity and minion smashing should keep Taric relatively well off until he can go back (I've lasted up to level 11-12 before I've ever had to go back before in some games). 2. Taric may need health before he gets his heal spell at lvl 3, camping the turret for a few moments allows quick health recovery without any mana waste from consecutive heals. 3. It builds quickly into the next item, Philosophers Stone. This is NECESSARY because of both the HP and Mana regen, but the 5 Gold per 10 seconds as well. As main support you are not going to be getting many minion or player kills, so to progress this is important. This is also why I grab Kage's Lucky Pick, ability power for shatter damage and heal strength plus another 5 gold per 10 seconds.