There are several addons that you can use to display raid icons for the members of your raid
GRID
HEALBOT
X-PERL
These are some of the more popular ones you could use
I use X-perl with the Clique addon to allow for mouseover click spellcasting. I also use Class timers to give me a bar to show the HoTs (and how many stacks of LB) I have on both myself, my target and any focus target I may have at the time.
For Example: I use Clique to set my Lifebloom as Shift+Left Mouse Button. I mouseover whichever raid member needs healing and hit shift + Left Mouse button and it will cast Lifebloom on that person without changing my target or focus. This is very helpful for raid healing as it allows you to cast as fast as your GCD will allow. I did the same for all my healing spells, rejuv, regrowth, swiftmend, etc...
An extra helpful thing I use in X-perl is the fact that you can set ranges based on your healing spells as well as set the icon to display how much health they are missing, percentages, if anyone else is healing them, etc...
Hope that helps you out some. The other addons I have never tried but have heard good things about as well. I am just happy with my X-perl (plus I like the ability to move my icons anywhere(including target of target/focus, and change sizes of icons. plus the character pics are cool how they actually reflect whoever the person is. I.E. their gear.)
Ok so I'm done with my X-perl addon plug. I like it. Good luck