If I use Time Machine to backup my Mac and then have to restore it later, will it retain the "Date Created" attribute of the files?
I can confirm that it does on OS X 10.9. I created a spreadsheet in November 2013, then deleted it a couple of weeks back. I've just restored it (because I didn't know the answer to this question!) and the Date Created says 17 November 2013.
Since Time Machine changes between OS X versions, I can't say that this will be the case for older versions, but I imagine it should be.