Check the level of brake fluid in the brake fluid resivior in the right rear of the engine compartment looking in from the grill of the car (hood open). Top up the resivior with brake fluid if required. If the fluid level is down just a little bit (enough to turn on the light) it may be a sign that the brake pads are low in material thickness and the fluid level has dropped to compensate. If the fluid is down a lot you have a leak in either case the car needs to be inspected. If the battery light and brake fluid/handbrake light is illuminated it is usually a problem with the charging system/alternator.
Finally I have seen the "float" in the fluid resivor stick. Removing the resivior and cleaning it solves this problem.