How to select the best printer drivers when sharing printers?

I need to share 7 network printers from a Windows 2008 server via TCP/IP. What would be the best way to do this?

There are about 25 clients, and most are running XP but a few have Vista or Windows 7. Most of the clients are 32 bit, but the server is 64 bit. I have tried going to the server and adding a printer, installing the drivers, turning on sharing, then adding additional drivers. This is where I get stuck. The server wants me to point it to where the x86 drivers are. Most of the printers are HP, so I looked for x86 drivers on HP’s site. There are several choices for each model – PCL5, PCL6, Post Script, UPD. How do I know which ones to pick?

Thanks for any help you can offer.