Question about factor analysis / PCA

Hi,

I have some data that I've been analysing using Principal Components
Analysis. What I'd like to do, though, is to find out how much each of
the actual dimensions of my original data (i.e. before I do PCA)
contributes to the variance in the data.

Also, I'm assuming that if I do that, then the variance contributions
of all of the original dimensions (factors?) will sum to 100%?

Sorry if this is a dumb question -- I'm pretty new to statistics.

Thanks,

Ben
.