Fiching with Alarms

I set up my alarm for the first time on Saturday (targetting 15lb+ carp),
using it for my second rod. Rod 1 was fishing floaters.
I had three takes and lost them all within seconds of picking up the rod!
It's probably a case of 'user error'...
The free-spool reel was giving line OK after the take, then I picked up and
snapped (3 times!!) - I think the snapages were probably due to a rather
clumbsey dis-engagment of the free-spool mechanism, anyway, can anyone offer
basic advice on using bite alarms??
Do I need to strike? When?
Whats the best way of dis-engaging the free-spool?

__
Matt