The Goods about having A Combat Annie as Support is she can be fairly mobile and she helps get your team fed. The trick with this build is to deal damage to the enemy, stun them with your passive, and let your team take the kill. The only problem with Annie support is that she lacks actual supporting abilities.

When another lane needs help, be sure to have a stun ready and TP over to their lane as soon as you're available. If you already have maxed boots, it makes assisting other lanes much easier due to the cooldown and buffs your TP and Flash gets. Be sure to stun with Tibbers or your Q, finish with you remaining abilities and let the other player get the kill. Flash is nice for this if things go wrong or if they begin to run before you can get to them. With the Maxed boots, flash gets a speed buff that makes you very fast.

When Team Fighting, Throw down Tibbers with a stun, your Incinerate, and the activate the Hourglass. After that, try to pick off any remaining enemies with your Q.