Blender's user interface is very flexible and often provides more than one way to do something. Many operations that can be done by clicking on buttons and menus can also be done with keyboard shortcuts called "hotkeys". The hotkey is usually much faster than the corresponding mouse action, so it's a good idea to learn them as soon as possible.
An entire WikiBook (titled Blender 3D: HotKeys) is devoted to Blender hotkeys. We encourage you to refer to it as often as necessary.