This link will lead you to legislative history materials for the Patient Protection and Affordable Care Act (H.R.3590) on the Congress.gov website run by the Library of Congress.
The Robert Wood Johnson Foundation Web site includes a number of articles and reports regarding the Affordable Care Act. To locate these resources use the search box to search for "affordable care act."
This site contains a wealth of information on health reform.
Print Resources
Law, Explanation and Analysis of the Patient Protection and Affordable Care Act: including Reconciliation Act impact. CCH 2010. This two volume set can be found on the first floor in the stacks at: KF1183.A369 2010.