Connecting AirPort Express Base Station to Time Capsule
I do not have an Airport express (or Time Capsule...), but the method is not as scary as you might be worried about.  First, setup your wireless network on the Time Capsule, make sure the settings with regards to B/G/N etc are ones that your Airport Express can read (you don't mention model numbers), so ensure you are not using N only if your Express cannot do N also.  Network mode should be "Create a Wireless Network".  Then, on your Express, set the mode to be "Extend a Wireless Network" - it will list the networks it can see (that it is capable of extending, hopefully), and with luck you will find that they are within range of each other.  You just need to apply the same settings re passwords and security etc here, and hey presto it should repeat the same wireless network, thus extending it's range.  The network settings tab within Airport Utility should be greyed out, as the device should just be passing on what the Time Capsule presents, and it's not capable of overriding them.  Anything you subsequently plus into the ethernet port should effectively drop you into the same LAN, using Wireless connection between the TC and AE to allow communication from your telly to the internet.