The bitaddress.org site is said to be clean. I don't exactly doubt it, but I wouldn't stake my retirement on it. There is also the possible peril of a key logger on your system. Best to save the website code to a clean USB stick, boot a networking -free Linux live DVD, and generate and print your wallets from there.

Note that I have never audited the bitaddress code - again, think about whether it has been properly vetted.