The usual selection is WPA-PSK TKIP -- it's pretty much the default wireless security at the moment and you shouldn't have any issue except with very old equipment or Apple stuff. I suspect the problem is with different terminology being used by various manufacturers.
I would start by checking that you can connect with wireless security disabled.
What is the make and model number wireless NIC in your laptop and what is the make and model number of the wireless router? Linksys router use a hexadecimal key and some wireless NICs use either ASCII or hexadecimal keys. What band are you trying to connect on. Is the router broadcasting the SSID and make certain the is no MAC address filtering on the router.