caster with pets?

hey im new here. havent started the game yet, but ive been looking at potential builds and havent seen any using a caster (elemental or monk) as a primary backed up by a ranger pet to tank for the caster. Can sumone post pros and cons for this idea?

Cons: Pets are awful tanks and take up a good portion of your skill bar
Pros: .....

I am new at the game so I can't give all the in's and outs but I played beta the last one they had and I played a Elemental/Ranger and I loved it. Defintly picked it cause of the pet. It helped a lot. One major problem is that the pet sometimes didn't attack first like I wanted it to. Also couldn't figure out how to rename the damn thing. I sure hope u can.