This is the first post in a series of tips and tricks to healing regular ol' 10 man Naxx. Basically, just an outline of things I've noticed to be quite helpful. =]

First up in the Arachnid Quarter is a cute cuddly giant beetle named Anub'Rhekan. He has a few annoying abilities, but myself (in blues and greens due to my lack of WoW time ><) and a resto druid were able to heal through them all just fine. As a priest, keep up PoM and use Levitate to mitigate the fall damage you will receive from Anub's Impale. When scarabs spawn from corpses (10 from a Crypt Guard, 5 from a player) wait a tick and use fade to send them scurrying back to the AoE'ers. You may want to toss a shield on one of the AoE'ers but really, the scarabs have so little health that it shouldn't be a problem.
When Locust Swarm is about to come up, max range the tank. We had ours kite him around the room, and I stayed on the edge of the middle circle farthest from the tank and was able to heal just fine without getting Swarmed.
Top off your DPS as they get Impaled, keep the MT and OT healed. Range Locust Swarm. Fade off scarabs. The end!

Next is Grand Widow Faerlina! Once again, done with myself and a resto druid. We had our warrior tank OT the Worshipers, whilst most of the DPS stayed on the Widow. All switched to the Worshipers to avoid Frenzy, then went back to dodging Rain of Fire. Basically, for this fight, it's pretty straight forward for us healers. MT and OT will need heals. Slow DPSers will need heals, maybe a shield if they decide to run into the rain, instead of out of it -.- Poison Bolt Volley hurts, and if you have a poison cleanser in the raid, make good use of them. Whoever if afflicted with the poison will take about 4k damage initially, and then have a nasty DoT ticking for around 2000 every 2 secs. DPS her down before 4:45 is up, then, grab your loot and move on.

Maexxna is, /sigh, another spider boss. Sadly, your Death Knight's Death and Decay (as of Dec 2, 2008) will fall to the floor beneath her web and not do very much at all. But, no worries, they should have no problem keeping aggro. We had a hunter specifically designated to get rid of the Web Wrap, and, I found that a single flash heal was good enough to keep them alive, if it's all you can do at the time. For this fight, don't stand in front of her so you can avoid her Poison Splash, and keep up Renew for when you are caught in her Web Spray, otherwise, your tank could be lacking heals for 6 seconds. At 30% Maexxna will frenzy, dealing double her normal damage and attacking half again faster. Still, keep up renew, have your poison cleanser abolish any and all poisons they can, and keep the raid topped off best you can. Afterwards, grab loot and move on.