Most Taric guides rely on his tankiness. I prefer seeing Taric as a main healer. Although he can run out of mana pretty fast if he spams his heals, careful itemizing and planning can negate that problem :)

Eye of the Oasis: Good CDR with (imo) the best gold support item in the game. If you are going to play as a healer main as opposed to tank main, you need to go with Ancient Coin anyways. The mana regen from the coin will keep you in the lane for a very long time.
Ardent Censer: Pretty well known item for healing/shielding/buffing.
Knight's Vow: Very cost effective. Gives your adc an extra layer of protection so that she can stay alive a bit longer as you spam your heals.
Manamune: The most controversial item in the build, helps with your mana problem and very effective with your passive. Keep spamming those heals while nuking those adcs :)
Boots: My personal choice. Might go for Treads or Tabi depending on enemy composition.
Righteous Glory: Very useful active to engage and dictate when/how you will be fighting those team fights. Extra bit of health and armor helps the kit all around :)

Lane Freeze. That is what you need with Taric. Pushing your lane opens you up to easy ganks as you don't have much in the way of escape mechanics and you should prefer catching your enemies mid lane instead of forcing a dive under their tower.

Always keep heal ready. Autoattack minions and use that passive to reset your 2 stacks after healing your ally. You may need to steal a minion or two from time to time, it is worth keeping your heal ready. Getting up to 4-5 stacks helps you keep your team alive while waiting for your ulti to kick in.