Can I add more computers to my router by connecting another router to my original router?

Router #1 (which I am using holds 4 computers). I want to add 2-3 more computers and add wireless capability for my PDA. Can I connect Router #2 (4-ports with WiFi) onto one of the ports on Router #1? What do I need to do to set this up? What is this called? Please help :-P

Can I add more computers to my router by connecting another router to my original router?virus removal

Yes. Read your docs.

Can I add more computers to my router by connecting another router to my original router?anti virus protection

You, you can do it. You'll have to turn off DHCP in the second router and make sure they have different internal IP addresses. That's it.
router you on about?
Add a hub to your router, and a wireless access point to add wifi capabilities to your LAN.

The three following links will so a router with a 24 port hub, a wireless access point to add-on to your router and third an 8 port hub.
Yes, that is possible. It is called an access point architecture. The easiest way to do it, is to plug the ethernet cable (a cross-over if I remember correctly) from the internet port of the second router to one of the outgoing ports of the first router.
just set the second router up like you did the first one... and have the input of the second one go to one of the 4 on the first one...
Buy a switch. Switches are cheaper and you do not have to turn off DHCP.
You just need a Hub, if you use another router I think they would interfere with each other since both would want to administrate the net and assign IP addresses.

By connecting an access point, you can have all the wireless computers you want to your LAN.