Hey,
To set up your network, the easiest way is to connect both laptops via a Cross-Over Cable cheap and can pick up from jsut about any Computer shop. Only problem with this is that you will have cables running through your house. Or you cna buy a wireless Router not so cheap, but cable free (NOTE: If your laptops do not have built in wireless you will need PCIMA Wireless Adapte Cards or USB Wireless Adapter)
Once you have this you can begin to setup your network, with the router it should have built in DHCP and should auto assign you an address. With the Cross-Over Cable you will need to set your IP Addresses automatically, this can be done by going to the Properties of you Network Connections, Right Clicking you Ethernet Connection, Click the TCP/IP Section then Properties and put in the IP Address of 192.168.1.1 for one computer then 192.168.1.2 for the next. Subnet mask of 255.255.255.0 on each and no default gateway.
That was settings your computers IP Addresses, now you must add them to the same Workgroup. This is done by Right Clicking My Computer then going to Computer Name Tab and click the Change button. Change the Workgroup name the bottom section to WORKGROUP (NOTE: This must be the same on both computers) then it will ask you to reset your computer click Ok and it should reset for you, if not manually reset.
Now you have to same IP range and same workgroup you should be able to access your documents. To share your documents via to network you will have to Right Click on the Folder you would like to Share and click the Sharing Tab. The Steps involved with this should not be to difficult. Now to access the files accross either computer you can either go to Network Places and click workgroup computers or you can type in your brwoser either 192.168.1.1 or 192.168.1.2 depending on which computer you need to access.
Hope this helped and with itunes im not sure after you create the connection on a way you may use the itunes program to access the music through this, but sharing the folder the music is stored i will allow you to play the music just as well.
Thanks,
Josho