Moving iTunes files to external hard drive

I have a mid 2009 MBP with a 500GB hard drive and I am running OS X 10.8.2. My iTunes file has grown to almost 300GB and I need to move it off my MBP and onto another hard drive. I purchased a LaCie Porsche Design 1TB hard drive and tried to move my files on to that hard drive. I am having a lot of issues with my MBP no finding the external hard drive and in addition to that it is a pain to always have that hard drive dangling from you MBP. Is there an option to move all your iTunes files onto an external hard drive and point iTunes from various devices to that external hard drive? I already have a time capsule. Would a second time capsule dedicated to iTunes do the job? I'm running iTunes 11.0.1. Any advice or suggestions would be greatly appreciated! Many thanks in advance!