To connect a device to a Wi-Fi network, you first need to know the name of the network and its password if it has one. You may also need to know the type of security implemented on that network.
To add a device running OS X to a Wi-Fi network, go to the menu bar, click on the Wi-Fi icon, select the network you want to connect to from the list, and then enter the password if the network requires one. Click Join to connect to the network. If you can't locate the Wi-Fi icon, enter System Preferences, click on Network and choose the option to display the icon in the menu bar.
To add a device running Windows 8 to the Wi-Fi network, go to Settings and then tap or click the network icon. Choose the network you want to connect to and then click or tap Connect. If a password is necessary, enter it and click OK.
To add an Android device to your Wi-Fi network, go to Settings, tap Wireless & Networks, and turn on Wi-Fi. Afterwards, go to Wi-Fi, then scan for Wi-Fi networks in range. Once you've located the network to which you want to connect, tap on it and then tap Connect. If the network requires a password, type it in and tap Connect.