Integrated Control Panel
The Integrated Control Panel (ICP) is a set of buttons located prominently at the front of the cockpit, directly underneath the HUD. The ICP is used to control the Data Entry Display, and can also be used to set the master mode of the aircraft.
If you are not using your HOTAS, you are most likely using this to interact with your plane. By default, most of its functions are on your numpad.
Arrowkeys on your keypad are RTN - SEQ and UP and DOWN of the ICP Dopper. Also known as DCS Data Command Switch - 4 way hat switch below the 8 and 9 keys on the ICP. Described in the DED section.
Your numpad + and - are the functions of the rocker on the lower left. Enter is enter, and numpad keys correspond to the functions ingame.
HUD Brightness Knob - this is the knob marked SYM in the upper left corner of the ICP. It is used to control the brightness of the HUD - clicking on the knob increases the brightness, and right clicking on it decreases the brightness.
A-A and A-G Buttons - these buttons are used to control the master mode of the aircraft. Pressing either button when the aircraft is in NAV mode will set the aircraft to the air-air or air-ground mode. You can press the button for the selected mode again to put the aircraft back into NAV mode.
Drift C/O Switch - the pitch ladder on the HUD is usually aligned so that it is centered on the flight path marker. If the aircraft is in a situation where the nose of the aircraft is pointed in a significantly different direction than the actual flight path (for example, during a steep turn) the pitch ladder could be partially off the display or not visible at all. However, if this switch is set to DRIFT C/O, the pitch ladder will always be centered in the HUD, regardless of the position of the flight path. (C/O stands for "cutout" by the way).
Other controls on the ICP used in conjunction with the Data Entry Display, are described on that page.