[NoobToPro]

Hi there.
I have decided to take up electric guitar.
As far as I know, all lead electric guitartist played songs mostly by fingerpicking right?
Hmm.. after reading lessons in this forum, what i wanna know is that when we fingerpick a particular song, how do we know which string to pull from a particular chord?
Cause when i search for tabs/chords in ultimate-guitar, it did not tell me T R I M (as taught by kirk's lesson) or P I M A (by fretsource lesson) in their tabs.
So how am i supose to know which string to pluck if its never stated?
Pleease help me in terms of words/images.
Thanks A LOT in advance.