Can someone help me figure out how I can incorporate my new Time Capsule device into my existing LAN network so that I can connect it directly via Ethernet cable to my network to provide for the fastest Time Machine backups possible, but also configure it so that it extends the signal range of my existing wireless network?

My current primary router (D-Link DIR-655) was obviously not setup using the Airport Utility (v5.3) so I have zero understanding of how the Airport Utility works, nor do I know what settings need to be custom configured to suit my needs as I've stated above...

Any suggestions would be greatly appreciated... Thanks!