Comcast Cisco DPC3008 Modem & Time Capsule Unable to Create Working Wi Fi

I do apologize if this answer is somewhere out there in the support forums, I've read everything I can find - but have not been able to solve this issue.

Here is the set up:

Comcast installed our high-speed internet yesterday via the Cisco DPC 3008 Modem (non-wireless). Hard-wired via Ethernet cable the Internet connection is fast and works. But, we need wifi.

So, I connected the TC via the Ethernet/WAN port to the DPC3008. First two times I never got past the blinking amber light, then I powered down the modem and the TC, and upon powering back up I get the steady green light on the TC and all lights on the modem are as they should be with only the link blinking with data transfer.

We have 2 x Macbook Airs (one - OSX 10.7.5), two iPhones all running iOS 6 w/ Airport Utility installed, and an iMac for which I can't find the darn power cable (we just moved), and an Apple TV.

On my iPhone (4S), the iPad, and one Air I can "see" the TC via Airport Utility - and it shows status of green. However, while I can see the wireless signal from the TC, the wireless network shows up in the network utility - I can't actually connect to the Internet. Interestingly, when I use an ethernet cable from the TC LAN port to the Air, I still can't connect to the Internet.

I'm guessing that something is wrong with my settings, authentication - along those lines. I did a soft reset on the TC which didn't seem to resolve anything. (We do have oodles of data including the other Air's back-up on the TC, so I don't wnat to accidentally erase everything that is on there.)

On my Air the network utility says there is no IP address for the TC network, although I have an IP address/Router IP and Subnet which I can pull when looking at the TC from my iPad. My guess is that those are the TC settings and somehow not the WiFi network settings, but that's a huge guess on my part.

Any super-ninja networkers who could help would be greatly appreciated.