I have an RPi running XBMC attached to a Samsung TV. Furthermore, I have a large HDD attached to the RPi by USB and an Edimax WLAN adapter in the other USB port. What I want to do is to be able to access (read & write) the files on the HDD using several Windows 7 computers in the same network. Some of these computers are attached to the network via WLAN and others via Ethernet cable. The RPi is currently attached via WLAN (but could if necessary be attached via Ethernet cable). Only a very simple setup is needed (only one username etc.).
What would be the best way to do this. Specifically, what is the best (but still convenient on the Windows side) technology to do this (Samba, FTP, SCP, ...?). Does the filesystem on the HDD matter (currently it is NTFS but it could easily be reformatted)? Does it make sense to connect the PRi via ethernet? What is the best OS on the RPi (currently I run XBian)?