Illusion Vs Domination

Ive been playing for about 2 months now and I have a warrior/monk build that I love but I wanna try something new. I have made a mesmer/monk that is currently a level 4. I know that I think im going to choose fast casting and either domination or illusion with healing prayers.

What is the difference between domination and illusion? I am going for pvp but I dont think im going to go after casters, I think i wanna go after warriors.

Well both dominationand illusion can be effective against warrior, it's all depend of how you want to play, im sure you can make a great build while watching the skills of the mesmer.

You can take a look at them here

http://www.guildwarsguru.com/skill.php

For pve purposes, domination is definitely the way to go. As a mesmer, you're really expected to have backfire to help take down tough boss monks. Also, shatter hex is practically spammable, and is one of the strongest aoes there are, it's amazing when you're up against monsters that keep your party hexed most of the time, which covers almost all mob groups. Can't forget chaos storm, the mesmers only normal aoe. It may be weak for an aoe, but it's still important to get some worthwhile damage in.

Illusion is mostly single target, slow spells, and degen, none of which are all that great in pve.

About taking healing, I highly recommend that you don't. You'll NEED inspiration to support your primary mesmer line energy-wise, without it you won't have the energy to be an effective domination mesmer, let alone heal as well. No one will expect you to heal anyways, and heals don't really benefit from fast casting. Just use your monk class for unlimited res and unlocking.