Because my older sister bought a print and I want my sister to hook it up. So I can use with my laptop, and my sister can use for her laptop and computer.

No matter what if it's a older printer it has to be physically connected to one PC. After that all you have to do is (on the PC its connected too, assuming your on the same network) allow that PC to share that printer to other devices on the network, have your PC connect too it and you should print perfectly. If you need more detail let me know. I'm rather drunk may be explaining in too broad of terms.

I have a printer that is attached to a USB hub and the USB hub connected to the back of a PC. When I want to connect the printer to my laptop I simply unplug the printer cable from the USB hub, then I connnect the cable to my laptop which is very easy to do.

Do you have a wireless router?

Yes I have wireless router. Why do you ask?

To make sure you can use a wireless printer. Most printers sold today have built in wireless capability. If the printer your sister bought doesn't have wireless capability then there are two ways to go. Either what darkvision suggested; connecting to one of your computers and sharing it or getting a wireless print server abd cinnecting the printer to that.

My older sister says it have a USB cord for it.

If your sister is using a USB cord then she is connecting it directly to her computer. For you to share it you need to follow the instructions darkvision gave.