There are a few things you can try before calling us. If your kitchen sink is backing up, pour a few pots of boiling water down the drain. Sometimes this will help break up minor obstructions. A plunger will do the job occasionally as well. Plug one side of the sink and plunge the other. If these suggestions don't work, you will most likely need a power auger. A manual hand cranked auger will rarely clear the obstruction within the kitchen sink drainage.
If your tub is backing up, a plunger can be useful here as well. Make sure to plug the overflow so there's a proper seal and plunge the drain.
If your bathroom sink is backing up, you can try the same method as the bathtub.