Many provisions of the Affordable Care Act (aka Obamacare) will take effect in January 2014, so now is the time to start preparing. The Healthcare.gov site maintained by the Centers for Medicare and Medicaid Services explains the basic tenets of the law and who will now be required to purchase health insurance.
The site's Health Insurance Marketplace won't be available until October 1, but starting your research now will give you extra time to shop and compare plans later on. If you have questions, there's a link to chat live with an expert who can help you. There is, of course, a remote chance that Congress will eventually be successful in its attempts to repeal some or all of the Affordable Care Act, and if that happens, this site will surely tell you about that too.