i think making it 3gb will be more than enough
As a rule of thumb, it's a good idea to only use matching RAMs in the two slots. 3 GB implies having 2+1, that's a bad idea.
@Metalloy, give it time, you will discover thing as you go. There are neat mac apps you could check out:
– TextMate (if you're a coder)
– Notational Velocity (if you're a minimalist)
– CloudApp (file uploads)
– Ecoute (if you think iTunes is a beast)
– Reeder (awesome RSS reader)
– Kaleidoscope (if hdiff is too ugly for you)
– Vox (neat little audio player)
– F.lux (fights insomnia)
– Caffeine