How do online Auctions work?

Hey Folks, I was hopping someone could help me with som questions i have, well i was leasing a vehicle, and with the way the Economy is going im not able to keep it /ubbthreads/images/graemlins/bawling.gif but w/e so i started to look for a new car from dealers and toughs buy here pay here places and still no luck, but i was told by a friend to try out the online Auctions so i started looking and found click
which looks OK but that's not the point, i want to know if anyone knows how these online auctions work and if anyone knows of any good one? Ty in advanced
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