It can be really useful to group similar Apps together in folders to make them easier to find when as you build up the number of Apps on your iPad.
Press and hold on the icon of one of the Apps you want to place in a folder until they all wobble like jelly on a plate.
Drag the icon on top of another App that you want to place in the folder.
A folder will automatically be created (magic!)
Give the folder a name and tap outside the folder to return to the normal view screen. You can now drag any other Apps into this folder.
If you want to take an App out of the folder, simply tap on the folder and then hold down on the App until it wobbles. Then drag the App out of the folder. To get rid of the folder completely, drag all the Apps out of the folder and t will disappear (poof!)