When you get a router and it has a wireless capability (it will have an aerial at the back) it will allow you to connect your laptop or wireless (wi-fi) equipped PC via a LAN cable or wirelessly
You need to find out the name of the router's wireless ID (called the SSID)
To see this, log into the router using a browser with the router's address, ie
http://192.168.1.1. To find the router's address, run the Command Prompt (CMD from Run) and type ipconfig /all. Look for the Gateway. This is the address
There will be a login and password, typically Admin/admin
Look for Configuration / LAN / Wireless. Look for the SSID and type in something recognisable, ie jonnys and APPLY
Then look for Wireless Security, preferably WKA and put in a PASSCODE - again some numbers you will remember - like 9876543210, and APPLY
Then your laptop should look for a wireless network with the name you gave it, so click CONNECT and enter the passcode