If you are looking for a way to learn a little bit more about your iPhone or maybe have a question about how a specific feature works…you might want to check out Apple’s iPhone User Guide. It is a nicely iPhone optimized user guide with a ton of info. The User Guide’s web address is http://help.apple.com/iphone. You have to be on an iPhone or iPod Touch for the Guide to display correctly.
This is a built in bookmark as well when you get an iphone.
This has been bookmarked in Safari since the 2G iPhone it’s bookmarked on iPod Touch as well but completely different guide.