If your guild asked you to betray to Warden and their request was enough for you to do it - I'd ask them what they had in mind and let that guide how you choose your AAs.
As a new Warden, and therefore speculating that you probably aren't STR spec'd, nor do you have much in the way of STR gear - you might not want to do the melee spec right off the bat..because you'll wonder wth is the big deal with melee if you only have, say 50 STR. For that matter, you might eventually wonder wth the big deal is with melee anyway, but..I digress.
If they want you to raid heal - as a new Warden, you'll probably not want to spec melee there, either - again, it'd be a gear/experience issue since healing in a raid while melee-ing is (IMO) kind of tricky if you are new to the concept.
That said, I usually advocate taking every choice that helps you heal better - if that's the role they want you to choose.
As for your spell list request, I'd suggest going to
EverQuest II Players there's a tab that says 'spells' and every spell for every class to 80 is listed. You can refer to that list while in game using the /browser command, for a quick look when you level and for when you are shopping.
They must have asked you to betray cause someone wanted your uber buffs.. Yeah, that's it.
Good luck with your new class, though. It's one of my favorites...god help me.
Avielle Eyrikson
80th Warden, Mayhem (AB)
Dreadnaught Ariel Demoras
70th Warden, OMG I'm Drunk (Venekor)