Apple User Guide for iPhone 4 and iOS4
As you noticed, there was no manual or users guide in the box with your iPhone 4. Or in the OS update if you installed it on your iPhone 3G/3GS. Like Apple has done for years, the guides are online, and in this case you can grab the PDF from Apple here.
This is no small little ‘tips’ book. Over 200 pages are broken down into 28 chapters. It has all the usual items about using the built in apps, and has been increased from previous guides to include the little short cuts and quick tips that the new OS provides. Quick muting, placing calls on hold, locking the screen orientation, swipe for audio controls and many more…