So it looks like you want to configre a PSK network? if that is the case edit your SSID and go to the Security Tab for the SSID you want to change.
Under this table set 'Splash page type' to None
Then set the 'Encryption' type Enabled, select your key managment, WPA2-Personal for PSK, and enter your passphrase. Save the profile, and you should be good to go.
If you want to make sure the guest are sperated from corporate nework, under the 'Access Tab' set it to Network-Based, and configure ACLs to block traffic into your corporate subnets.