I see mention of perks a lot, but don't know exactly what they signify. (I've only got in about 60 hours of play and know I'm missing a lot of things that might benefit me.) I notice perks are awarded with level increases, but can you get them in other ways, how are they applied and what do they do? Is there a game-play manual somewhere that explains this sort of thing?
Another question: Where can you see your levels in various skills, things like heavy armor, destruction, etc?

Every time you level up you'll be prompted to open the menu abd level up you character, choosing an increase in Magicka, Health or stamina. In the background you have diagrams showing each discipline of advancement in the game, from Combat to Bartering. You gain one Perk for each time you level up to. You use that perk in any one of those trees of skills in order to purchase special increases and abilities.

If you have somehow been playing along unaware of this, then you'll have a fair few Perks available to spent.

If you're on the PC, hit Tab and you'll be able to choose to level up from there. Use the mouse key to navigate around the different perk trees. Once you enter that menu, you'll have to increase your mana, health or stamina (probably several times at this point), but you can save up perk points to spend at another time. In fact, I advise this, as you can't undo perk points spent, and you'll want to put them where they'll do the most good.

I'm sorry, I'm not familiar with the controls for either of the consoles.