Are you better off using robes or armor? I want to be a mage that uses a single handed sword or mace.
I am just curious If I should be upgrading my robes or use armor.

I'm primary a weapon user, but swap to spells every now and then to keep things fresh.

Best combination would be Frostbite in left hand and weapon in right.

To actually answer your question...

I would personally use robes so that you can get a bonus to your magic and then use a shield spell. This way you will get the armor bonus and still get the magic bonus.

I'm using a robe for now, but I'm learning the enchantments of differents robes so I can apply them on a better light armor, and have better protection with magicka bonuses.

robes are pointless in this game (unless you invest in alteration and want to switch to and cast shield spells constantly), because you can enchant mana regen on heavy armor. And heavy armor doesn't reduce your magical abilities AT ALL. really stupid imo but eh

I decided to make my mage an assassin as well, so I switch between spells and daggers. At the moment I'm sticking with robes and casting shield spells anytime I get into trouble. As soon as I get my enchanting up I'll be enchanting light armor and going with that.

I do agree that it is a bit silly that armor does not interfere with spell casting, but meh.

thanks everyone, so robes and shield spells for the armor boost seems to be the way go go for the beginning until I can enchant

Heavy Armor + Destruction all the way. Focus is on my one-handed Sword combat though.

I have the same set up, spell on left, weapon on right. I am using armor currently because I'm playing on expert and you really can't get through some of the fights without armor, as some people will kill you in 2 hits if you're wearing a robe.

Yeah I have an armor set as a back up if I can not get through a certain part with just robes.

im using a novice hood with steal armor and its working pretty well with lighting bolt in one hand and an elven mace in the other