How does critical damage work in Diablo 3?

I see a lot of skills (runes) with effects on critical damage and it seems you can potentially have builds based around this alone.

1. What are the chances I have to do critical damage?
2. How can I see what my critical chance is?
3. Does every direct damaging skill have a chance to do critical damage?

Solution 1:

1. Depends on many things including your skills, class, magic affixes, etc.
2. Open your Inventory and click the Details button. It's under the Offense section, which is at the top.
3. Yes.

Solution 2:

You can find all of the information including chance to do and damage done by a critical hit in the details screen. This can be found by opening up your character tab and then clicking the details button on the left side under you basic statistics.