There is no help on Apple site for new users of an iPhone. You have to look for it elsewhere.
1) The Missing Manual (iPhone: The Missing Manual) – Covers from the tech in the phone to multiple ways to do almost everything
2) My iPhone (My iPhone (Covers iPhone 4, 4S and 5 running iOS 6) (6th Edition)) – Maybe a touch less tech coverage than The Missing Manual, but not by much
3) iPhone 5 for Dummies (iPhone 5 For Dummies (For Dummies (Computer/Tech)))- A reasonably comprehensive guide that doesn’t bog down in tech detail and covers fewer ways to do things than the missing manual
4) Teach Yourself Visually (Teach Yourself VISUALLY iPhone 5 (Teach Yourself VISUALLY (Tech))) – just a how-to usually one method per function
5*) iPhone 5 for Dummies for Seniors (iPhone 5 For Seniors For Dummies (For Dummies (Computer/Tech))) – A moderately distilled version of the dummies book with more focus on “senior specific” topics