In a 5-4 decision (with Chief Justice Roberts being the swing vote and writing the majority opinion), the central provision that all American people should have healthcare has been upheld. Here is the court ruling (pdf).
Here is some recommending reading across the web:
Supreme Court lets health law largely stand (New York Times)
The history of the US health care reform effort (Huffington Post)
Here are some books available in Sullivan Library about the US Supreme Court:
Regulatory rights : Supreme Court activism, the public interest, and the making of constitutional law (catalog record)
The Supreme Court and American political development (catalog record)
The Supreme Court in the American legal system (catalog record)