The newest update to iOS 7, iOS 7.1 is finally available for download. Apple updated its website with information relevant to the update, visit it here: http://www.apple.com/ios/ios7-update/
You can update your iPhone, iPad or iPod through iTunes. You can also update your device via wifi. Just go to Settings>General>Software Update>Download and Install.
Here is a list with all the improvements, bug fixes and new features.