Welcome to iPhone 101, where TiPb helps new iPhone users use their new iPhones -- or just gives you a handy link to send to your new iPhone using friends.
This time we're tackling something near and dear to every child-caring adult's heart: how to resent your iPhone Home Screen to default. Because as we all know, you let your child at your iPhone, and they can switch around your icons -- even blank your Home Screen -- in no time flat (and yes, the above is a real screenshot of an iPhone after a 3 year old spent about 5 minutes on it...)
Luckily, there must be a lot of parents at Apple, because they've made it lickity-split simple to restore.
From the home screen, tap Settings (yeah, if you can find it -- but at least they can't delete that or any built-in application).
From Settings, hit General, then choose Reset.
From the Reset menu, choose Reset Home Screen Layout. When it asks you to confirm, tap the big red Reset Home Screen button.