If you need mobility with your laptop, smart phone, net-book, etc. or you would like to reduce the number of cords and wires attached to your devices, then go wireless. Wireless comes in a few different speeds, A/B, G bands which operates on the 2.4GHZ frequency, and the newer faster N which operates on the 5GHZ frequency. Most wireless routers are backward compatible and support older and slower speeds. Best solution is to buy the latest model wireless Router to have wider coverage for all devices. Linksys which is owned by Cisco is the standard equipment widely used in homes. There are many other other brands out there, but I would recommend Linksys for home use. Belkin, Netgear are others well known.
Choose your network hardware. The primary piece of hardware required is the wireless router. As mentioned above there is the older speeds of A/B (1st Gen up to 11mbs) and G (2nd Gen up to 54mbs ) and the newer faster N (3rd Gen up to 108mps). Once you decide on the router you will need a network card in whatever device you intend to connect to it. Smart phones and any laptop made in the last couple of years will already have them built in. If you already have wireless built into the device and you buy the latest router you should be fine. If you have a laptop that has a "N" card then you need a router that has ''N" speed as well. A special note here. To get the maximum speed out of any wireless band you usually have to have the same brand of network cards and routers. Due to the faster speeds now available this is not as much as an issue as in the past as it was with A/B band speeds. You can stream video without issue and perform file transfers quickly with the G band. The N band is even faster.
Connecting your router to the Internet. There should be a port on the back of the router labeled "internet" and one labeled "WAN" on the back of the DSL/Cable modem. Use an Ethernet cable to connect from the DSL/Cable modem to the router. Turn off your cable/DSL modem by unplugging the power cord in the back of it and turn off the power to the wireless modem. Once both are powered off and the Ethernet cable is connected plug the power back to the cable/dsl modem. When you see lights on the front of the modem start lighting up then go ahead and power on the router.
Here comes the hardest part which is configuring your router. Turn off/Shut down your computer. Connect your computer to the router by plugging an Ethernet cable into the computer and plugging the other end into the back of the Wireless Router. You should see some ports on the back of your router which are normally marked 1-4 or so depending on how many ports you have on the back of the router. You can plug the Ethernet cable into any of the numbered ports. Next, turn on your computer. At this point the computer will obtain an IP address and connect to the router. Open a web browser window and enter the router's IP address in the browsers address field. The routers default IP address, default user name and password can be found in the routers owner's manual. Once you have accessed the routers configuration menu, you will need to select a network name (SSID), enable encryption (network key) (either WPA or WPA2) whichever encryption you use you will be asked to make a key or it will give you the ability to create one. Change your administrators password from the default setting so that only you can access your router to make changes.
Be sure to change the SSID name to something that does not identify you and write the SSID name and network key on the bottom of the router for future use. You will need to know this key when setting up wireless devices to the router. You also have the ability to hide your SSID from broadcasting which is an even more secure way of locking down your wireless router from people trying to surf on your internet or trying it hack into it. This is the preferred method, but it will require you to supply the SSID name when connecting a device since wireless items will not "discover" it on their own. Also when you change your Admin password use something not easy to figure out. Don't use your home phone number or an easily figured out name. Make it hard. Use numbers and letters and possibly a combo of Caps and lowercase letters. Write the SSID, Network key and password on the bottom of the router. Trust me you will need it again and don't make the mistake of trying to think you will remember it. You won't remember it when you need it and then you will have to go through the process of setting the unit back to factory settings and reconfiguring the router. When done configuring the routers settings close the browser and disconnect the ethernet cable from your computer. The router will restart once the configuration process is complete.
Turn on computers and other wireless networking devices that you want to use on the network. Wireless devices will attempt to join any network that is in range, specifically, the network with the strongest signal. Once your network is detected, you will be prompted to enter your WPA/WPA2 password before you will be granted access to the wireless network. If you chose to hide your SSID you will have to manually setup your wireless connection. There will be a place on your device to do this where can submit the information. Once you make the connection you will also be able to check a box on your computer to make your new wireless connection the preferred wireless connection. FYI. If you have desktops that have built in network cards and you want to install a wireless card all you have to do is install the card, install the drivers and follow the same process above as you would a laptop.
With wireless speeds increasing yearly wireless networking is the way to go to reduce clutter and get rid of all the wires. One note on wireless. Wireless has a range of several hundred feet out in the open, but once it installed in a room/house walls, brick and other obstructions can and will reduce speed. Also the farther away you are from the router the speeds are decreased. Good things is that wireless speed has increased tenfold over the last 5 years and will continue to get faster so these issues will eventually decrease in severity, but they are things you need to be aware of when troubleshooting connections