It is a hexadecimal number between 8 and 63 characters in length - e.g. af16af3c75f3edc8ad0ab27c58. The more characters the stronger the key! And no, that isn't mine!
Note that some routers allow you to type in a word or phrase that the router then uses to generate a hex key. The attached devices must use the hex key, not the original phrase.
WPA-PSK takes any string of 8 to 63 characters, not limited to a hex number. So could be Th1sI5MyWPAP5KK3y. And no, that is't mine!
WEP takes a phrase that generates hex keys.
As Saab said, your network name suggests WPA-PSK so if you look on your router and enter the same phrase into the Blackberry it should be good to go.
Upper & lower case characters are important, and it can be difficult to get the numbers and letters in the right places if you're not confident with the Blackberry keyboard yet so take care.