If you need to connect a computer to a wireless network then before you actually connect just make sure that you are using a computer that has wireless capability (all laptops will have this but most desktop computers wont), Also make sure that you are within range of your wireless network. As a general rule if you are inside and your wireless router is within 50 feet of your computer then you should be ok to connect
In the lower right hand corner of your computer (next to the clock) you will see a network icon (Windows 10) , It looks like this or if you are using Windows 7 look at the 2nd image:
When you click on the above icon any available wireless networks will show , The networks with the strongest signals will be at the top. You may have several available networks in the area, As a general rule of thumb your network will probably be at the top of the list - In the example below we can see that the network called CNC_Wireless has the strongest signal and is therefore the network the user probably wants to connect to
To connect you simply click on the network and select Connect (and to disconnect highlight the chosen network and select disconnect).