I read a lot, and my memory often helps reminds me of where I last read the quote or stat that will be most useful. I can't always find what I remember, but I still often find exactly the source that I am looking for because I know where to look.
Useful Sources for Political Debates:
Intellectual & economic arguments for less government: Walter Williams, Thomas Sowell
Public transportation & government planning is bad: the Antiplanner
Historical arguments for limited government: Burt Folsum
Guns save the day (examples): Guns Save Lives
Guns save the day (statistics): John Lott
Pro-freedom stats, figures, examples, studies, etc.: use a search engine to search for "[your subject] + Mises Institute"
Commenter Amy Haines left the best description of a debate that I have ever heard on my first post about debating advice:
It's not about convincing your opponent, or about winning the argument. It's about winning over the audience, and giving them strong pause to reconsider their assumptions and check their premises.
Those few links should get you started in any political debate. When you read some articles that have good data, save it. The data that is there may be of use to you later.
Please do let me know if you know of a good source for healthcare facts.
On a final note, If you want to know how to act and how to use statistics in a debate, then I suggest that you watch a debate that Dinesh D'Souza takes part in. I'm not endorsing everything that he has said, or done, but his debating ability impresses me like no other debater does. (He first appears, with an opening statement at around 25:50 into this debate.)