Recently, on the iOS Developer Network (iOS DevNet) on LinkedIn, I posted a discussion on integrating "social media hubs" into your iOS 5 app and provided some references. Here is the discussion:
There are several ways to integrate your app with Social Media hubs like Facebook and Twitter. Now with the new Accounts and Twitter frameworks in iOS 5 Apple makes it even easier.
Peter Friese has a good post on his blog covering Accounts and Twitter integration.
Lasse Bunk shows another example using JSON and Storyboards in Xcode 4.2.
More information on Working with JSON and iOS 5 can be found in Marin Todorov's post on Ray Wenderlich's blog.
You can, and should, review Apple's document on on the Twitter Framework and the Accounts Framework to become familiar with the new APIs.
In addition, and if you like the feel of paper, or use the Kindle
app, Amazon is now caring Apress's Beginning iOS Apps with Facebook and Twitter APIs: for iPhone, iPad and iPod touch book.
Cheers and good luck on your app's social integration.