"..I just opened the valves and the faucets and stuck the air hose nozzle and blew away. Is that all I do?"
Not hardly pilgram....you need to install a fitting that takes the male end of an air compressor hose and screw it into the water line, at the faucet, or better yet a short "t" in the actual water line which you then can attach your compressor to and shut all valves to the system except the one you want water to rush out of, and then blow away.
Your hardware man should be able to set you up with the fitting, complete with a throw valve which shuts it off when you are using the water. Once you have it installed, you shut all but one faucet or spikot, and open up the valve inbetween the air hose fitting and water line blow it out and then shut the valve again.<font color="ff0000">•</font><font color="ff0000">•</font><font color="ff0000">•</font><font color="ff0000">•</font><font color="ff0000">•</font> doesn't get much easier than that.
Some places have the whole plumbing system set so it self drains at the low end of the system...and that is the best there is....open it up and leave. Shut again when you get there and turn the pump on while your there and the place has heat....or in the spring.
btw, the above temperature alarms need a land line phone line to call when the temps drop...I own one for that and one that auto dials when the power goes off....both are great pieces of mind, and work well.