There are no classes in Skyrim; you basically just level up certain skills to build your character to fit your playing style. I am a warrior in light armor, and I wield a one-handed weapon. When you level up, you get to pick a perk for a specific skill. This perk can be anything from 20% extra damage with a certain weapon type to a 15x damage bonus when sneak attacking with daggers. Thus, when I level up I choose perks for one-handed, block, and light armor.