[R] plotting gam curve against predictors

[Sonya Ku]

Hi 
I am just beginning to learn R and have fitted several GAM to my
species presense/absence data.

I have used plot(x,y) using fitted.values as a y variable against
predictors. However, it is hard to see general relationships where
there is wide spread in predicted values for any x.

So I'd like to 
1) plot general curves, not individual fitted values against predictors
2) have some indication of confidence interval 95% but this is optional

would greatly appreciate any tips

Sonya.