I'm not an expert but I hope this helps, since you are just getting started then just farm and get legendary (red) items. I started with summoner but I switched to skullshield. Besides the insane damage I found it very easy to play and now that I have more experience I'm looking for new builds but for starters I recommend it.
I'd recommend you to hire ( I started with a rogue but switched to wizard..), the reason was that I wanted to get more items for my wizard .
I can't post my noob build right now but basically: elem dmg, weapon dmg (on the offhand since I use skull shield). Then the red affixes: glasscannon, barbarian and push the limit will give you tons of dmg too (push the limit and barbarian cannot be rolled you have to get an item with those affixes afaik..)