If for example you have all your music in your home computer, and you'd like to listen to it at your office computer, you need to install pulpTunes only in your home computer. After installing it, start pulpTunes (still at your home computer). You will see a message giving you an internet address. Take note of it. You'll also see a link to a website (portforward.com) that will give you some instructions on how to configure your home router to be able to access pulpTunes from outside. I'm afraid this step might be a little complex. Let me know if you need more help here.
Then, at your office, just open your favorite web browser, and write the internet address I told you to take note of. You should be able to see and hear your music.
Cheers,
Alejandro