Before calling a plumber, try to unclog your drains and toilets yourself by using a plunger. Make sure you use a standard bell-shaped plunger for your sink and shower drains and a plunger with a flanged end for your toilets. If neither type can loosen the pipe blockage, put a plumber's snake to use. Ratchet the snake down the pipe to eliminate any clogs.
We called Mr. Rooter because we had a leak from our kitchen sink and they responded quickly to my surprise. Mike Farnsworth shows up and gets right to work and doesn't give us an estimate for the work before he started. He ended up replacing a broken pipe in our basement that took 15 minutes and he plunged our tub and sink as well. He wasn't even here for an hour and he charged us $650 dollars! We refused to pay that much because it wasn't reasonable, so he took us to court and he ended up lying in front of a magistrate claiming he worked for 2 hours and did all these repairs, even though after he had left the sink was still leaking and the drains did not work at all!