Itunes, External Harddrive, and Home Network Questions

I have my itunes music folder on an external harddrive connected to a PC that I access thru a home network. everything is fine there. Here are my questions:

1. I have 2 mac laptops...if I add music to the external harddrive thru the pc, will itunes update the library on my mac when i access the external harddrive thru the network? and if it doesn't, how would i be able to do this. Example: If "laptop 1" adds all its music to the external harddrive, will itunes on "laptop 2" automatically update its library and show the newly added music when connected to the harddrive?

2. If i have music on my laptop and want to play it when im away from home, do i just need to change the itunes music folder location to where it is on my laptop? And when i do this, will there be any problems? I have a copy of the itunes library file on both my laptop and external harddrive, if that matters?

Thanks

1. You want the pc and 2 macs to share the same itunes music folder and have all 3 share the same library.xml file so that all can update it

Solution for OS X
http://lifehacker.com/software/itune...ive-238296.php

Solution for windows
http://lifehacker.com/software/itune...ork-230605.php

2. when you are on the road you want itunes to work locally

You can reset the path to the local music folder in prefs and use the alt key on start-up to point to your local library (or you could have 2 user accounts, one local one networked but that might not be ideal)