If you're healing with Sorcery then I'd say the main thing is to make sure you've got Circle of Protection and Boon of Souls, most of my healing comes from them, Soul Well is also great, especially for large trash packs as it heals extra every time something is killed in range of it, along with its small periodic heals. Rejuvenate is obviously very useful for spot healing when a single person takes burst, but it's far to inefficient to rely on as your main source of healing. I quite like Invocation of Renewal for raids, but with the long cast time I don't think it has much of a place in alerts, so I generally swap it out for something else outside of raids.
The rest is down to preference really, the Watcher should be mandatory if it is patched so as to not despawn randomly, get stuck, or killed constantly. But for now it's quite hit and miss.
Also, if you're having trouble with Power, try and pick up some handblasters, outside of exploiting sweep shot, it's the best for getting your combo up fast for the power regen.