My advice...go Breton with resto-staff and play the NB as you would a Sorc. the only skill you really need is resto-staff healing and Siphoning... and off you go.
Forget about blades of all kinds and Shield.... forget about sneaking and being an assassin. assassin skills and blade skills work fine on single targets... get two and you are in trouble...get three and you are dead. I am talking about same level targets.
with the resto staff and the siphoning tree skills i can solo four targets with a little bit of running about.
forget also about blocking..as a ranged NB there is plenty of time to avoid most spell damage by just running out of the way. Okay...facing a melee fighter now and then you going to sit on your backside...who cares with all the healing available.
Health and magicka are your friends... since you not not need to sneak and seldom to block...stamina is not really required.