I am new to comics and just got a whole bunch of them for the holidays. How do I read them?

I have never opened up a comic book besides Watchmen. My friend gifted me a bunch of these "New 52" comics and I am pretty excited to begin reading them. The only problem is, I don't know where to start.

I have 4 different ones that have Batman on the cover (and a black guy). They're called Batman, Batman and Robin, Batman The Dark Knight, Batman Detective Comics, and Batwing. Then I have 3 Superman titles in Action Comics, Superman, and Supergirl.

Then there's all the Justice League ones. I am so confused. Do they all take place at the same time? Should I read some before the others? What does the black guy have to do with a bat?

Any help would be appreciated. Thank you in advance, from a comic newbie.