Accessing 2 computers in the same house

I'm no wiz at this, I have two computers connected to a linksys wireless router. I put the wireless pci card in my sons computer and it worked fine for awhile. Then it quit. So I ran a cable from one of the ports on the back of the router and hardwired him a connection through the walls. One day I might figure it out what happened. I now have a spare computer and would maybe like to try to set it up in my garage in direct line of sight about 50' from the router. Do you think it would work?

Also, I have an older printer (HP 712c) and he has a newer photo printer. Can I configure our system to share the printers? If so how?

Thanks in advance!

 

Failed to mention, my son is running XP Home and I have XP Pro on one computer and W98SE on the other. I have not decided which computer to use just yet (listed in sig. line) trying to decide which one to keep.