Yes it's quite simple with a ftp program..have a good read of this..sorry, it's linux but deals with windows too http://www.aboutdebian.com/network.htm
yeah, you can do it without any programs at all really, if you have Windows XP. You just need a crossover cable or a wireless connection. you have to do what is known as mapping your drive. You do this on both computers and set them up to communicate with each other. Then any files that you want to be able to access you have to enable sharing in the options. My Laptop is linked to my PC that way through a wireless connection. So i can do things like stick a movie in the laptop, use DVD Shrink to copy it, and copy those files to the PC rather than the laptop hard drive into my shared folder. http://support.trittontechnologies.com/tutorials/mapdrive.html http://support.microsoft.com/default.aspx?scid=kb;en-us;308582 http://www.icaen.uiowa.edu/tools/etudes/mapping_drives.html http://www.uwplatt.edu/oit/howto/mapdrive-win.html hopefully those can get you started.
Just as steimy described use the search feature and find the computers near you on the network then map the drive or use the search and "\\computername goes here" w/o quotes of course and that should link you to whatever folder is being shared.