specialty: magic
attributes: strength, intelligence
skills:
1.illusion
2.destruction
3.restoration
4.conjuration/athletics
5.block
6.heavy armor
7.blade
birthsign: the lady
First - light armor is fine, and eventually gives you just as much protection as heavy. In the early game in particular though, you have to be conscious to not just stand there and get hit, since it doesn't provide much protection until you get your skill up a ways. LIght armor characters need to depend more on mobility and less on protection.
For the build:
I'd almost certainly trade off intelligence for endurance. Bretons get plenty of intelligence as it is, and it's probably the easiest attribute to increase. Endurance is vital early game, and particularly for a character who's going to be fighting up close.
I'm not sure about the specialization, but I'm shying away from magic. Spec really should be picked at the end rather than the beginning, since it depends on majors, so I'll come back to that.
Illusion, destruction and restoration are all fine.
Conjuration is pretty good. It can increase a bit quickly if you use it a lot, but the high level summons are worth it, in my opinion.
I wouldn't pick block. Again, a lightly armored character is better off depending on mobility than on protection. You're better off moving away from attacks than blocking them.
Heavy armor? Was that supposed to be light armor? I definitely wouldn't pick heavy (other than as a placeholder in a majors as minors build, which I assume you're not doing). Light armor would make sense though.
Blade's fine.
I'd tend to swap block for armorer, but otherwise it seems fine. As for specialization, the first thing I'd wonder is if you're planning on using other magic skills a fair amount as well. If so, then magic would be okay (though that'll tend to make conjuration a bit more difficult to manage). Otherwise, I'd tend toward a stealth spec. That'll give a boost to light armor (and sneak and security and so on) and keep your magic skills from increasing so quickly that your battlemage becomes a mage. I'd even consider a combat spec, for the bonus for blade, though that would leave light armor a bit too slow and would potentially make armorer a problem.
The Lady is okay, I guess, but willpower really doesn't count for much early in the game. I'd lean more toward the Warrior (to make up for the Breton's penalties) or the Mage, just because extra magicka is always a good thing.