A number of healers have asked me how I have Grid set-up, so instead of walking through each person how to set it up, I figure having a post set up is ideal.

Step 1: Get the add-ons

Grid:

Curse - Grid
http://wowace.com/wiki/Grid

If you use Grid, I recommend also grabbing these:

Curse - Grid Side Indicators

Curse - Grid Status Hots
(See my patched version for 3.1:
Mythical GridStatusHots 3.1 thread
)

Curse - Clique
Clique is only semi-related to Grid, it is an addon that allows you to bind things to clicks. So you can bind Cleanse to right click. You can bind trinkets like Living Ice Crystals (shift right click for example).

Step 2: Configuring Grid

I have my Grid set-up with:

Two lines of text: The players name on the first line, and status on the second line.

I have indicators for:

Aggro

Incoming Heals

Disease
Poison
Curse
(I have these indicated separately because they used to be different spells and they still are when I am enhancement spec).

My Riptide

Regrowth, Rejuv, or Renew (so I can prioritize my heals on someone who isn't getting hots)

Setting this up:

Right click on the Grid Icon
-> Select Frame

First, at the bottom:
Advanced
Check:
Enabled Center Text 2 Indicator,
Enable Icon Cooldown Frame,
Enable Icon Stack Text,
Enable Mouseover Highlight

Center Text Length: 8
(At least it used to cut everyone's name short by default, I like to see the first 8 latters)

Border
Check:
Low HP warning,
Your target

Healing Bar:
Check: Incoming Heals

Center Text:
Check: Unit name

Center Text 2:
Check:
Death Warning
Debuff: Ghost
Feign Death Warning
Health Defecit
Offline warning

Center Icon:
Check:
Debuff type: Curse
Debuff type: Disease
Debuff type: Magic
Debuff type: poison
Ready Check

Top Left Corner:
Check:
Aggro alert

Top Right Corner
Check:
Debuff type: Disease
(This will depend on your class)

Bottom Left Corner:
Check
Buff: My Riptide
(This will depend on class)

Bottom Right Corner:
Check:
Debuff type: Poison

Frame Alpha
Check:
Death warning
More than 10 yards away
More than 100 yards away
More than 30 yards away
More than 40 yards away
Offline warning
(This effects how dark the box is, the further away they are the darker the box)

Top Side:
Check:
Buff: Regrowth
Buff: Rejuvenation
Buff: Renew
(I only have the powerful hots selected here, weak hots like earthliving will not alter who I heal)

Bottom Side:
Check:
Incoming Heals

Left Side:
Check:
Low mana warning
(An alternative to this is to install GridManaBars addon, but that will use more of your resources constantly updating everyone in the raid's mana)

Right Side:
Check:
Debuff type: Curse
(This will depend on class)
(If you noticed, I have all 3 types of debuffs I can remove along the right side, top right, right side, bottom right)

Layout:

This is where you alter the size of the raid you are in
This has "frame lock" to lock and unlock the Grid window
You can scale the sizes of your boxes

This section is so much to personal taste and the resolution you run, that I cannot really help you set this up.

One nuance though, raid vs. heroic raid, there are two different layouts based on whether the current raid difficulty is set to normal or heroic. Sometimes when starting up a raid and you are still in Dalaran it will be set to the wrong thing so you will end up increasing your normal raid size to 25 just to see the raid fill up.

I personally like to use the w/ pets layouts. This is required for fights like Malygos, but I always like to try to throw pets heals if no raid members are in danger. This will probably be moot in Ulduar as I won't have the heals to spare there, but useful other places. Obviously other than very specific fights where a pet is being used for a reason (like a warlock pet used when a warlock is tanking) players should always be higher priority heals than pets.

Status:

I do not believe that I changed anything in this section from default.

I should go through this section with someone and double check if I changed anything.