it depends mostly on your armor/jewelry enchantments, make sure you have enough mana/health/stamina boosts in them this mostly does the trick and of course spend your ap wisely

Well, as mentioned, maybe you need more enchantments/buffs that focus on magicka. However, I'm also betting that you're only using Nightblade skills on your hotbar, and that's probably your big issue. You want to have at least 1 or 2 weapon skills there to use when you're out of magicka but sitting pretty on a full green bar of stamina. You can't rely on just one type of damage dealer.

I just keep running out of MANA though... I just don't have enough MANA... MANA... MANA... lol magicka. w/e...

Thanks for the tips. As a lvl 10 with only enough money to slowly keep upgrading the bank slots... I mean I have everything from woodsmen, smithing, clothing, enchanting, alchemy, provisioning, and all of the stuff from the imp edition clogging my inventory. I can't afford to NOT upgrade my inventory spaces. That and the fact that the one crafting item that I just don't have a lot of is rawhide; what I need for medium armor x_x. Level 10 just doesn't have a lot of decent enchants (besides the fact that I NEVER get armor specific runes... EVER!)

This is a consistent issue for everyone to be honest. I followed the suggestion of putting every point into health until I realized I could live through most anything but it took me a year to kill a damn critter. Use a couple pieces of cloth and spend a skill point or 3 on mana regen lines and put a few points in mana. The first few rings I found were mana regen as well.

since late in the beta, i have found that NOT spending your points (attributes or skill points) until you know for sure what you need, is best. sometimes i would have about 3 points in my pocket, but when i came across a situation that, required magicka/stamina/health i would spend one point at a time to fix it the problem. doing this i can take 1-2 mobs 8-10 levels higher than me, and not do too bad. dont neglect the passives either, they can sometimes help out.

Part of the joy ( rage? ) of combat in ESO is ... resource management!!

If all of your slotted skills require Magicka, make sure you're stats and armor boost that resource. Try mixing up your skills abilities between ones that use Magicka and Stamina.

You have to find a balance between regular heavy/light attacks and special abilities. With the variety of armor and weapon combinations this will be a hit-and-miss / try-it-and-see evolution.

Once you get into your twenties, your magicka shouldn't be much of a problem. Craft/buy max magicka food if you don't have it, it really makes a huge difference.

At OP: The integration of weapons skills into the hotbar is essential to managing resources. Also, you might want to think about how you're going to play. Are you going to be a mage or a dual wielding DPS? I focus on the latter; someone tonight explained they were doing the former. Both in the nightblade class - that's the "beauty" of system.

If you want some advice on dual-wielding: I've created 4 characters, all dual-wielding, in four different races and with every one (Breton, Dark Elf, Wood Elf, Khajiit) I've found the game quite easy. I use these five skills:

Dual-Wielding:
Twin Slashes
Flurry

Nightblade:
Strife - Siphoning
Agony - Siphoning
Assassin's Blade - Assassination

To level 10, I've never run out of magicka. I do buff myself in stamina, though, because I rely heavily upon Twin Slashes and it's later morph Blood Craze. I run a sequence like this:

Strife (from a distance), TW, TW, and Strife or AB for the kill. Sometimes I'll throw Flurry in at the end if the enemy is not dead yet.

I hope this helps.