[X-Newbies] Mac..Itunes..Ipod..moving music to external drive

[Thomas McDermott Jr]

Good evening,
	Am hoping someone..anyone?? could offer some assistance to this 
question I have.  I have a powerbook that has a 40 gig hard drive and 
most of that is being used for music for my ipod.  I have an external 
drive that was formatted for use on my PC that I would like to 
somehow reformat to copy over my music files from my itunes on my 
mac.  Would then like to, when I sync my ipod, copy from whats on the 
external drive instead of whats on my powerbook.  Does that make 
sense??  I am just not sure how any of that gets done..mostly, how do 
I get my ipod and or itunes to look on my external drive instead of 
my powerbook's HD?  If that is easy to do..is it even possible to 
leave some music on powerbook for when I travel but not have the ipod 
sync from there?


Thanks very much in advance

Tom