So many perks and skills in this game are cryptic in their wording. Is there a source that fully explains what many of them actually do?

Limbsplitter - how much bleed damage over how long?
Disarm - what % and is there a "level cap" per level? Each time I try to use it it says "resisted".
Fire breath - what's the damage rating?

There are more - but someone will inevitably complain and call them spoilers. Skyrim wiki just compiles the cryptic information provided by the game and displays it all at once.

I really wish Bethesda actually put some time into telling us what a lot of these (any many more) abilities actually do.

bump

Try: http://elderscrolls.wikia.com/wiki/The_Elder_Scrolls_Wiki

bump

Most are based on your level so their power grows as you do.

It's possible that people have done extensive testing to find the values which might be around the net somewhere, otherwise we probably have to wait for the editor to get access to the actual values.