Auto-siphons are freakin' amazing devices. Pump twice and the siphon is done.
The trick to any siphon is positioning more than anything else. The top of the bottling bucket needs to be below the bottom of the carboy, otherwise the siphon will stop once the level of one reaches the level of the other.
As far as starting the siphon at first, what I did before I had an autosiphon was to get sanitized water into the tube by submerging it, dropping the racking cane into the carboy and pointing the filled tube into a piece of tupperware or something. The water will pull the beer up the racking cane and as soon as it reaches the top, the siphon is pretty much started. Once the beer starts coming out, you can squeeze the tube to halt/slow the flow, then quickly move it over to the bucket and let it go.
It can be tricky, and you WILL get stuff on the floor so set everything on top of a towel. Get someone to hold the tupperware container if you can.