I am not sure how to look for this on the forums-- I tried searching for druid spells and cleric spells, and even spontaneous spells, but nothing came up. And really all that I want to know is this:

I remember from PnP campaigns, my cleric could spontaneously cast a heal spell by giving up one of her memorised spells, and that a druid could summon an animal the same way.

Can I do this in NWN? if so, how? (and if there is a thread on this, Please link it! Thank you so much.

EDIT: Okay so I figured out accidentally. Apparently you just drag the spell (ie summon/heal) to the quick bar and then it will cast. O.o.

To set a spontaneously cast spell for a cleric, the player must drag the spell from the spellbook to a quickslot. These slots will have their number of uses (top-right corner) displayed as "S", indicating that the slot represents spontaneous castings. (Technically, the "S" designation only appears when the cleric has no memorized uses of the spell remaining, but this is usually the case as players never need to explicitly memorize spells that can be spontaneously cast.)

From http://nwn.wikia.com/wiki/Spontaneous_cast

OMG! I should have tried wiki! Thank you :)