So, recently, I've found myself playing a lot of Skyrim and I've always liked using bound bows in that game. Some-time down the line, I fond myself wondering where bound weapons actually came from, how they worked and why I could use them. So, here I am, posing the same questions to people who know much, much more than I do about the how and why of these things. I look forward to finding out more!

I guess that they work in a similar way to summoning creatures only that this time you summon an item and not a living thing.

The bound weapon/armor is a lesser daedra bound into that form by the summoner.

They are actually living Daedra. When you summon them they get twisted in the shape of a weapon or piece of armor.

EDIT: http://www.imperial-library.info/content/darkest-darkness

What dictates the form they take? Are the limits the summoner's imagination and the power of the daedra summoned? Or is it to do with the spell itself and, if so, could a mage craft a spell that would allow them to dictate the form the daedra took when summoned?

I will add my own question here, are the conjured skeletons and zombies also daedra?
It can't be necromancy, the conjurer doesn't even need bones or anything.

Bound weapons are good for a character with low stamina such as a mage & battlemage or a magic based Nightblade as they are weightless.

Conjuration magic seems to depend entirely on taking Daedra from Oblivion. My guess is that, when summoning skeletons and bonewalkers, you take a Daedroth from Oblivion and shape it into a different form, much like using a bound weapon. Otherwise, I'm just as stumped on that question as you are, R'ahnjil.

Well, typically when you're summoning undead, you're summoning them from the Soul Cairn. Or at least, the "Outer Realms". This was first explained in Oblivion, I believe, and was displayed in a more direct fashion in Skyrim.

Thank you people.