Andriod online multiplayer tutorials

hi everyone,

I have a question…
I really like to try to make a andriod game…
it would be a photo challange game, where a group of people can connect there phones to each other’s, make a couple of photo’s and then vote who has taken the best picture…
and i have alreaady found a lot of tutorials who will help me out with the most things…
the only problem is that i can’t any good tutorials for internet functionality…

so my question is: do you guys know any good beginner tutorials about online multiplayer on andriod devices?

it doesn’t have to do any really conplex stuf.
the only thing it need to do is: share picture’s over different devices, run a simple voting system, and keep up the score…

already a big thx for reading and thinking! ;D