XING-like db app

Hey guys,

In order to make our small business network available on the iPhone, I (a total Objective-C Newbie *cough*) am now supposed to write a native app.
I am sure most of you know XING and it's iPhone app. As far as I know, that app works with a continuously updated database (similar to our business network).
I would now like to know if it is possible for a newbie like me to write a XING-like app, containing messages, contacts and so on and, if that is the case, how I am supposed to start with it.

Thanks in advance,
Lyceron