Peacebringers are very variable, I don't think there's a guide that covers all the ways you can build them.
There's a Tri-form guide here that is a good place to start if you're curious about powers.
If you're just looking for a Slotting/Power Pick guideline though, try Sherksilver's Hero Builder... can download the normal executable from the Program's Home Page or a slightly more accurate version from my webspace. (Several powers are tweaked to show correct stats for accuracy/recharge/endurance/resistance/defence)
The most popular build is probably Human/Dwarf, but there's plenty of Triformers and Pure-Humans out there. The overload of power picks means that two PBs will rarely be identical, even if they've taken the same forms.
I went Human/Dwarf on my PB, but I've got a second one on the drawing board that's a Triformer.
The PB build I have at the moment is a triform - I just can't bring myself to respec out of the squid as my play style is more suited to blasting than tanking, so the Dwarf has become my panic button of a sorts, at least giving me armour enough to get out of Dodge if the heal doesn't save my skin and mean I can continue the fight.
What I was looking for rather than a build guide was just a simple list of which levels powers are unlocked at. I prefer for some strange reason to have pen-and-paper (Pre-MS Word writing implements for the less ancient among you) build plans, and for that I require a little list of what levels powers unlock at.
I am at work and my search-fu was left at home.
While I am at it and asking questions more suited to a n00b than a veteran, is there a bind expert out there can write the following for me so I can apply them when my sad and lonely 24 hour shift ends and I can go home and have a CoH session?
1) Bind onto number pad 1 - go to human form, go to tray 1 where my human powers are
2) Bind onto number pad 2 - go to squid form, go to tray 4 where my squidlie powers are
3) Bind onto number pad 3 - go to dwarf form and tray 5 where my dwarf powers are
I am also assuming that the tray you "go to" is the first tier one of all those you have open? I have three open already - tray 1 for human blasts and attacks; tray 2 for heals and shields; tray 3 for temps, travel powers and forms; tray 4 for squid blasts; tray 5 for dwarf attacks. All this confusion and only level 25!!!
"Pride is all well and good but a sausage is a sausage"
For Lent I gave up...
Hope
Here are the binds you asked about:
/bind NUMPAD1 "powexec_toggle_off bright nova$$powexec_toggle_off white dwarf$$goto_tray 1"
/bind NUMPAD2 "powexec_toggle_on bright nova$$goto_tray 4"
/bind NUMPAD3 "powexec_toggle_on white dwarf$$goto_tray 5"
...and another one for the hell of it; this switches you from squid to human and turns fly on, in case you want to do some heals and self buffs without landing on the head of whatever you're bombarding:
/bind V "powexec_toggle_off Bright Nova$$powexec_toggle_on Energy Flight$$goto_tray 1"
As far as what power appears at what level; if you run SherkSilver and hover your mouse over the power lists, you get "Available at level X" as a tooltip.
Cheers, Standoff. Thanks for the help.
"Pride is all well and good but a sausage is a sausage"
For Lent I gave up...
Hope
I bit the bullet... 
Here's the guide you wanted!
Thank you Maelwys, just what I wanted.
"Pride is all well and good but a sausage is a sausage"
For Lent I gave up...
Hope
Very good guide there
Proud member of FOXBASE ALPHA and coalition associates.
Hero 50's - 25
Villain 50's - 1
Is anyone able to point me in the general direction of a "What powers are unlocked at what levels" guide for PB's especially and WS too if it's been written. WS powers I find pretty intuitive to choose. PB's I feel need more planning and I haven't yet seen a decent guide for what unlocks at which level.
Cheers guys.
"Pride is all well and good but a sausage is a sausage"
For Lent I gave up...
Hope