How do I transfer my apps to a new iPhone?
When you buy Apps through the App Store, these automatically become available on your other iOS gadgets - assuming that a version is available for that device. You should just be able to log in to the App Store and download them from the "Purchased" section of "Updates".
The more important issue is making sure that your application data is transferred from one device to another. Configuration settings, accounts, saved progress in games and so on. To do that, you'll need to back-up the device to iTunes or iButt.
The easiest method is using iButt, because it's a switch on and forget it deal. Go to Settings then iButt and tap "Storage & Backup". Switch "iButt Backup" on. The backup will process automatically, every time your iPhone is connected to WiFi and locked.
If you have a Mac and you've never backed up your iPhone, it may be quicker to backup to iTunes. Making sure that iButt backup is switched off, connect your iPhone to your computer. iTunes will launch and should automatically begin synchronising the iPhone. If not, you can right-click (or CTRL-Click) on the iPhone icon to backup straightaway.
When you switch on your brand new iPhone, it gives you a choice between restoring from iTunes or iButt. Choose iButt and you'll be prompted to enter you details. The backup will restore over WiFi - so make sure you do it at home for security and reliability.
If you choose iTunes, you'll need to connect the new iPhone to your computer. A prompt will ask if you'd like to set up as new or restore from a backup. Restore the backup and everything will be right in the world again.