Could anyone please suggest the most important attributes and skills for a decent warrior build.
Also, what race would be best suited to it and what special advantages/disadvantages would be useful?
Any other points would be helpful.
:)

Playing a pure warrior like Barbarian or Warrior can be tricky because you will have to climb inside dungeons to explore all places and magic caster monsters will be your most fearsome enemies. Also you can't cast a decent spell for curing diseases and healing yourself. If you want to play a pure warrior make sure you join a temple and keep gaining ranks until you have access to the spell make. You only need to do one or two quests per month to gain one rank (can't go faster than one rank per month) so i would suggest alternating between a temple quest, a main quest and another guild you wish to join.

you'll gain as many ranks as you're eligible for, but you are only eligible for promotion once a month. so if you have the skills and reputation, you could gain 2-5 ranks at promotion.

Would it be a good idea to choose immunity to magic as a special advantage?

If you want an powerfull combo, try a High Elf and give him 'critical weakness to paralysis'. This is a big disadvantage, but since High Elfs are immuned to paralysis... You guess.

I'm doing quite well with this character right now:

http://i728.photobucket.com/albums/ww283/xuerebx/daggefallnew.jpg

Primary skills are Long Blade, Mysticism and Critical Strike.
Majoring in Thamautagraphy, Climbing and Blunt Weapon.
Minor skills in Running, destruction, shortblade, medical, swimming and dodging.

Special adv in using long blades and to hit against daedra.
Special disadv is that I can't use hand to hand (well it does 1 damage).

I was thinking of using critical weakness to paralysis as a special disadvantage to counter my special advantage (immunity to magic). Will it have much of an impact in the game?

If you play a High Elf, no. Else it will.

What about a nord with critical weakness to frost?

if you're using the high elf exploit, expect the game to play on easy mode.

nord's aren't immune to frost, so picking critical weakness ends up making the nord just low tolerance to frost.

athleticism is good for warrior characters, it equals less fatigue use, and better success with jumping, climbing, and swimming. also may as well pick an expertise in a weapon. rapid healing is awesome for warrior builds as long as you can compensate for the increased difficulty.