Not sure where you are but when I first started I really liked riding with actc.org. i think they're one of the largest clubs in the area. lot of rides for all levels of riders practically every day of the week.

you can find social rides, endurance rides, mtb rides and probably hammerfests (but these seem fewer. i don't know since i didn't seek those out). they are out of the south bay.

if you're in the east bay, i've had friends in the valley spokesman who said really good things about them. plus.. they put on the cinderella, which is awesome that they support this ride very year.