It depends on your definition of "organize" :-)
We've done fireworks a couple of times, but mostly in the amateur, let's have some fun, "Hey, watch this!" type affair.
It's pretty simple really. Buy fireworks (online), set the date and time, get your permit (I'm assuming you have somewhere to set them off), and on the date and time, let 'em go!
The permit comes from the vicinity fire department; it basically informs them of what you are doing and when.
We purchased fireworks from two sources. The first was from
http://kaboomfireworks.com Very helpful folks and site. The other we tried was
http://costco.ca
Costco fireworks actually seemed dangerous, we had many problems and things could have gone sideways quickly, if not due to some rather unique bits of luck. It was interesting that the manufacturer seems the same between the two sites, but the Costco ones seemed to fail and didn't look as nice.
The cost was about $450. We purchased lots of "cakes", it's like a whole bunch of fireworks in one. Fun lasts about 30 minutes or so, depending on how fast you light them, etc. We weren't necessarily looking for a professional display, more just have fun lighting them, watch what happens, so we go kind of slow. Other people liked lighting some of them too. If we manage do light it all off quickly, I'd imagine we would have about 5 minutes worth.
ers