What device are you using for your network (wireless a, b, g, n, or ac?)
What device and OS are you using to connect to the wireless network (laptop? phone? desktop with a wireless adapter? windows XP, Vista, 7, 8, linux, android, iOS, OSX?)
Most devices use DHCP so there are no network setting to mess with. Simply look for the available wireless networks, click on the SSID (network name) that belongs to you, select "Connect", and then enter your wireless key (password). That is typically all that needs to be done, but we need more information to help you further.
I have a wireless router and I'm trying to connect my laptop to it. Windows 7. My computer is seeing our wireless network, but when I try to connect I am told that Windows was unable to connect. Other computers in the house are able to connect to the wireless. I have checked and my wireless adapter in the computer is on.
How many devices (phones, computers, TVs, game consoles, etc.) are on the network? Is this a wireless router you purchased yourself (and if so then what model #)? or is it the piece of junk provided by your internet provider?