If its just for a Macbook and a PC you could just set up an SMB fileshare and keep all of your media in it. Then set up alias's (on the Macbook) and mapped network drives (on the PC) If your music is in iTunes you could just enable shared libraries in the iTunes preferences, iTunes on the Macbook and PC should pick it up and be able to stream over your home network.
If youre wanting to take your Macbook out and about with you you have a few different options including:
- cloud storage - (dropbox etc)
- setting up a VPN (allowing you to access your home network when not at home) although you'd need a very good upload speed for this.
- Some form of streaming system. There are numerous options but i use Zumocast as it has an IOS client and can be accesed via web browser