Yep, just do what AJ said. All you'll need is a flat-head screw driver and/or a phillips screwdriver to do the work. Easier to change it out then try to fix it. I've had a few here break in the basement here at Festung Scout and it always seems to break at the point the chain goes into the recoil mechanism.
Turn the light on and go turn off breakers until the light goes out. If your fixture has a outlet, buy a
polarity tester and plug it into the outlet. It'll show 1) if the wires are hooked up correctly and 2) is a double check as to that the circuit is dead. (Indicator light will go out when the circuit is dead.)
Then just unscrew the old fixture, check to see how the wires were attached to the old fixture, remove the wires from the old fixture, attach the wires (if the polarity tester should that your existing wires are switched around, you can and probably should make them right, but if it's just a lone bulb and outlet, it's not that critical) and then reattach the fixture. Plug in the polarity tester and go turn the circuit breaker back on.
If it trips immediately of smoke comes from the fixture, then it's all Fistful's Fault.
When it comes to getting help, I've found our local Ace here has guys who know their stuff (mostly retired guys who worked in the trades), the Big Box stores generally just have stock boys who are lucky if they know what general area of the store an item might be in.