Local HAM nets
Amateur radio is all about talking.
Hams like to talk; "nets" are a regular forum to talk about a specific topic
on the air.
There are formal emergency nets such as
skywarn, and ARES/RACES which handles
disasters of all sorts.
There are traffic nets, dedicated to passing written messages ("traffic")
between hams and non-hams, coordinated as the
National Traffic System (NTS) which operates under
methods and practices
developed over the years by ARRL.
Finally, there are informal social nets of all sorts.
ARRL: search for a net
SkyWarn
real time monitoring of dangerous weather
ARES / RACES nets
traffic nets
Socal nets
I've done my best to find a list of all nets within my listening range.
I've I've left out your favorite net, feel free to
drop me a line and I'll add it.