Brake Warning Light
This might only mean you've left the parking brake on. Or the trouble might be more serious, such as brake failure or insufficient brake fluid. Have a technician diagnose the situation.
Vehicles with antilock brakes have a separate light to let you know when there is a problem with the antilock system. This doesn't necessarily mean the brakes won't work, but it is likely that the antilock feature has a problem. Have a technician inspect the system.
Car Charging System Light
This indicates the battery isn't being charged. Causes can range from the expensive, such as a faulty alternator, to the cheap, such as a slipping belt. Take the car to a repair facility immediately.
Check Engine Light
Technically this is the malfunction indicator lamp, but it is usually labeled Check Engine or something similar. It indicates a problem with the systems that control engine functions. In some cars, it also monitors the transmission.
Usually the situation isn't verging on catastrophe, as the problems that activate the oil pressure or temperature lights can be. But you never know. Look at the gauges for a clue to what's wrong, and be especially alert to the way your car is running. If you determine that the problem means imminent trouble, pull over and call for a tow. Otherwise, take your car to a repair facility for diagnosis.
Airbag Malfunction or SRS Light
Not to be confused with the lights that let you know if the passenger side airbag is on or off, this light indicates that a sensor has detected a problem with the airbag system. When it comes on, have the air bag system inspected.