on this question it depends on what you want the outcome...!
firstly flaps normally are used to increase the wing area(get a camber below) and usually go down. it reduces the stalling speed, gives a nose up characteristic, and enables slow speed flying ...
above information is only partly true, and some things are wrong
a few things about flaps.
(a) when the trailing edge of the wing on account of lowering flaps goes down, the effective angle of attack of the air flow to wings increases and lift naturally increases
(b) Nose up or down will depends on (a) Position of tail plane (b) wing wake and it interaction on the tailplane (c) Position of CG.. generally a low winger will nose down. and high swept will go nose up.
(c) NO , a normal flap will not increase wing area, only Fowler Flaps does (Some thing like a telescopic flap)
(d) remember lowering of flaps will always increase drag and reduce glide distance, so if you have a cut and there is a doubt in reaching the field, DO NOT lower flaps.
there are a lot of flaps , please read up, Kreuger Flap, Single slotted Fowler, Double slotted fowler, Blown Flap etc readup, Boundary Layer Control.
There are much more to flaps. sometimes later.
However i go with Vishvesh, gliders requires lift dumper to come down upward movement of flaps is because of that.