That would depend on how often you will be printing, how big th printer is and whether you're in a network or not.
1) If it's a small-ish printer you could always move it around the house when printing is required - obviously this could be a hassle.
2) Install the printer on one machine and share it between the computers (if networked).
3) If you print very often and have a home network, you may decide that a print server would be more appropriate - less moving around, no (pc) server required when someone wants to print, but does cost a bit.
I'd say go for the first two options if you don't want to spend any money. But if you really want more convenience than anything, then a print server would be the better option. I chose this option because I have a wireless network and didn't to leave a pc on whenever my sister wants to print from downstairs.