taraweeh

[Ummu Sufyaan]

:sl:
well as ramadan is approaching, iam assuming many people want to/intend to pray taraweeh. I just needed some authentic info (as opposed to dong what i see everyone else doing). and maybe mu questions seem really....eerrmm... dumb and obvious, but i just wanted to make sure. anways, here goes. i've looked a little on islam qa, but they seem a little overwhelming.
Questions:

• what is the evidence that one can pray taraweeh
• What are the number or rakah's to pray.
• when should i pray these (time of day)

:sl: