Like people have said, Taric is quite good at the laning phase and weaker in teamfights. Here are some of my tips for Taric

1. Don't be afraid to use him to split push. It is risky, but if you win a good teamfight, pop over to a side lane and RW to clear the enemy wave and buff your minions.
2. Don't try to tank. You are durable, but aurastacking and flinging the occassional stun is your main role in a teamfight.
3. WIth that said, having one offensive item with an active can be really beneficial. DFG or even Gunblade give you a useful active that can help you participate more in a fight. Never take these over support auras though.