1) Is Windows XP Home's software firewall turned on? If so, it may be blocking ping.
2) For starters, is the samba daemon running? If so, are you having troubles with getting samba running or are you not sure where to start? If the latter is the case, the Samba FAQ (
http://us1.samba.org/samba/docs/FAQ/ among other places) is a good place.
Good luck!