Well yes their obvious but they also have a pattern.
I set mine out for my own comfort right click on the box gives u new boxes you can move by using F10
This is my comfy for me set-up.
1st box these are my main spells, we have a little spell thats heroic .... that is the second square across the top there
that looks like an ankh, its greyed out.
So my spell for nuke and heroic is
Root
Heroic
The blue arrows
the next down on the left
the next rince and repeat.
UNLESS I am solo and less than three mobs, I do my heroic combo for boooom nuke boom and can use the others
more than 2 mobs carefully pace out your spells or you are running out of power fast.
Combat regen is slow but then it always has been, so a tank will have more down time, but
and it is important, out of combat regen IS sped up by eating and drinking, don't use food and water
then don't moan about power
im so forward lol, my level 90 lecture included food and water
and we can get food (my little cheff is still very little) will be able to eventually make in combat food
(who the hell eats while weilding a sword i dont know but there u are)
My heals are all together and boy I use every one when were in a large group, especially my heal over time.
Good old dave takes quite a bashing :P
THE HEROIC:
Each of the spells on the heroic bar thing, flash, they flash so you know which to hit to get kabooom,
so put your flashing kaboom spells together, makes life far easier.