Warrior Mage Level and skill help

This is pretty much the same build that I've been using. I put a bit over half my total points into Magicka, most of the rest into Health, and very few into Stamina. I don't use many power attacks, and when I do, it's to finish the enemies off or stall for time while my Magicka is regenerating. It's working for me so far.

You will get enough perks to fill up 4 perk trees with room to spare, so don't worry about starting into another. I'm focusing on Conjuration, Destruction, Restoration, and One-handed, with a minor amount in Light Armor. Putting a point or two in a tree just to get a slight bonus isn't going to harm your chances of completing other trees.

Even if you completely focus on Conjuration, chances are you won't use every perk in that tree. You might focus on Atronachs over reanimating corpses, or you might not use bound weapons.

Just pick whatever perks you want and don't worry about it too much.

Here are my experiences in playing something similar. In my playthrough, I am a rogue/mage, relying on sneaking, dual wield daggers, and destruction (mostly for the trap runes).

The most difficult aspects to consider:

• Splitting your level into all three stats is very difficult, meaning you won't excel at one or the other. Heavy armor can offset the lack of health for a bit, but there's no getting around the lower stamina and/or lack of magika to cast lots of spells. Its a bit easier for me as most of my spells are cast pre battle (buffs and traps) and I rely on melee in fights, but its still not an optimal situation until your level becomes much higher.
• I wouldn't worry too much about which perks to advance, but do try to maintain a healthy spread of all your skills. This way, you don't level up nearly as fast and find yourself over leveled and facing enemies you shouldn't be facing yet. You can keep the perks until you figure out what you want to place it in, but try to focus on no more than 4-5 trees.
• Going the blocking/shield route might be beneficial since you will have lower health than pure warriors. Not to mention, the shield bash (along with any other knockback) can interrupt a dragon's flame attack.
• Conjuration is a great way to go as it summons additional meat shields for you, being able to dual cast a conjuration spell is a bonus as it'll make the summons last longer. I wouldn't worry too much about lowering the cost for higher difficulty spells as this is a pre battle cast and you can recover the mana relatively quickly.

I'm also a quite new player but here's what I focus on:

• Conjuration for Flame Atronaches and the awesome bound bow mostly
• Destruction for... well, it's a mage, if I don't use destruction what would I use?
• Ice against warriors, Lighting against mages and Fire for quick massive damages. I suggest strongly to build perks on ice.
• A bit of restoration can be really useful.
• Also you'll need to build a bit one handed for when you're out of Magicka.

My favorite build is:

4 points in Magicka and 1 in Health; 0 in Stamina. Repeat that pattern forever as you level up: 4 points on Magicka, 1 point on Health.