For your PC, you will need a external / internal wireless network adapter. This can come as USB for external or PCI for internal interface.
As for your laptop, you will need either a USB external wireless interface or a PCMCIA wireless card.
Pls ensure you get the correct card for your router as they are a few wireless protocol supported by different hardware being the most common known as ieee 802.11b and 802.11g also known as wireless-B and wireless-G. Check your router packaging.
the four port router will allow you to have 4 simultanues network connection to your personal LAN and also to share the internet (if any).
Pls try the comprehensive education site on wireless network and it's setup
for basic/beginner into it.
http://www.linksys.com/edu/
good luck.