Hey Bill, Welcome to the 281 family.. I can look in the manual for you, but its pretty vague and generic..
Just put the pump out hose on the pump out "deck fill", rear right corner of the boat.. Usually dont have to do anything but pump it until you cant see anything else coming out..
BTW, I have a beneteau 281 google group also, if you want to meet other 281 owners..Would be great to have you there also.. Its all a learning experience..
http://groups.google.com/group/beneteau-281
Cheers,
Sven
Beneteau 281 "Tradition"