Your money would've been better spent having the consultant teach you what he/she was doing...because then you could avoid issues like this.
Of course, DIY isn't for everyone I suppose. WEP and WPA are 2 different types of encryption. WPA actually has a couple of different sub-types of encryption. Out of the 2, WPA is the most secure. WEP encryption isn't that difficult for hackers within range of your wireless network to break. WPA slows down the performance of your router though, as it does a better job of encrypting wireless data.
When you access the router's settings, look for a link on the left that says wireless or security. Once you find it, you should see a dropdown box that shows either WEP or WPA (or some variation of). Below that, you will see a passphrase or key. If you are using WEP encryption, you might see a couple of radio buttons...one that says "Hex key" and one that says "passphrase" (or something similar). Choose to view the hexadeximal key...that's what you'll need to provide to your IP camera so it can join the network.
Now, the consultant MIGHT (if he/she was worth the money) have set up your router to only allow certain hardware (using MAC addresses) to join the wireless network. This makes your network much more secure. If this option is enabled, then you will also have to get the MAC address for the IP camera and add it into the "Allow" list on the router so that it can join the network.
If you can't figure it out, PM me your phone number (if in US) or Skype ID and I might be able to help you with it tomorrow. Once you know what to look for, it's pretty easy.