How long do I have to charge my mac book pro with retina for its first charge?

Just leave it plugged in until it's fuly charged and then you can run off of battery. Keep it plugged in when you're near a socket and don't let it drain down to reserve power.

You'll be OK...

Clinton

Here is a laundry list of battery and power information articles that tell you virtually all you want (and don't want) to know about same:

http://http://www.apple.com/support/macbookpro/batteries_power/

Ciao.

@OGLETHORPE - that link just takes me to www.apple.com - try again?

Clinton

Here's Apple's advice regarding batteries:

http://www.apple.com/uk/batteries/notebooks.html

http://support.apple.com/kb/HT1446