Addon: VuhDo, Healbot, or X-Perl

Of these three, I personally prefer VuhDo. These addons allow you to customize your raid frames to allow a more streamlined healing experience. There are options in VuhDo to also change the bar colors of units missing your buff or inflicted by a debuff. It can be customized 100% and requires a bit of tweaking to personal taste, but is definately worth the time spent. Healers, this one is mandatory : )

http://wow.curse.com/downloads/wow-addons/details/vuhdo.aspx

A character frame showing druid hots. Regrowth, Wild Growth,
Rejuvenation, and Lifebloom. All timers and stacks!

A character frame showing who beacon of light is on
and the tank cooldowns that have been used currently