As folk have said regarding the sequencing question, there isn't really a correct answer, moreso for someone who hasn't trained to be an ATCO. The best sequence I have personally heard is:
IF the aircraft were all equal distance from establishing finals, let the 737 down first, closely followed by the 747 and finally the Cessna.
End of the day, the wee Cessna won't use anywhere near as much fuel when it's up there doing it's thing circling. Also, the airliners give a helluva lot more money to the industry with their landing fee's and all, so essentially they pay more to land. And finally, the 737/747 crew and pax are already exhausted from what could be a 3-14 hour flight... The Cessna was probably up for fun, and they'd enjoy staying in the sky that little bit longer
