There are only some types of computer that will connect to certain types of wireless networks. Notebooks can connect to wireless networks like laptops do; just make sure your router is picking up signals and that its appearing on your notebook.
Wireless Networks
A bridge is a way to connect two networks. For example, if a user has two or more computers connected to a wired network, and one of those wired computers is connected to a wireless network, the computer connected to both the wired and wireless networks could be used as a bridge. With the bridged networks, the wired computers could access the wireless network.
War Driving.
First of reboot your computer, second try to update the driver for your wireless adapter. Also make sure that you are allowed to connect to those findable networks. If you can see the networks it does not mean that you can connect to it. Many people use secured wireless networks which protects networks from unauthorized access.
wireless
yes. computer networks
Usually wireless adapters can be connected to computers not to modems.
It depends on model. Some modems come with a wireless router. If yours has wireless interface, you will able to connect your computers wirelessly. Usually what you have is a modem with one LAN port. If you want to connect your 3 computers to the same modem you need to get a wireless router. It will allow you to connect your computers using wireless or cable. Switch in such case might not work because of internet provider policy.
If your talking about the Ipod Touch, it can connect to wireless networks.
Many Wireless routers and switches have few inbuilt switching ports capable of connecting Wired computers to Wireless Computers on the same network to connect wired Computers also alongwith. (Not necessarily every every wireless router will be having switching ports)
The computer itself must have a wireless adapter to connect to wireless networks. It is also necessary to have a wireless router, which must support the same kind of wireless communication as the adapter(a,b,g,n), although an ad-hoc network can be set up with only two computers and no router.
You can connect them with an ethernet cable, or by WiFi if they have wireless cards.