I'd be very keen to know how to develop a social game on android which includes 2 or more than 2 players. Let's say chess..for example or scrabble.How to begin? Are there any online resources or tutorials available on this subject?
The best resource out there is Google's Android developer guide: http://developer.android.com/guide/topics/ui/index.html
This not only gives you an explanation for all the major classes of the android sdk, it also gives you tutorials into things such as reading from contacts (specifically the "content providers" section).
As for sockets, I don't think there is anything special with Android's Java implementation for that, you should just be able to find any Java socket tutorial and use that.