There is an indicator for your health, armor, ammo for the current weapon, and currently selected or readied item or weapon. When you pick up something new, an icon will briefly appear at the bottom of the screen with a picture of that item. To view all of your inventory, press the Tab key. To get it back, simply press the - key. Quake II will talk to you from time to time.
Some messages appear at the top of the screen.
Certain messages will appear in the middle of the screen. This details your unit location, your primary objective, secondary or current objective, kill ratio, goals completed, and number of secrets found. When your field computer receives an update an icon will appear at the bottom of the screen. Be sure to regularly check the computer for information on progressing to your next objective. This is a special area that list all of the game messages, and allows you to give Quake II commands that cannot be given through the menu.