the router
In the Internet browser I have to enter 192.168.1.1 to get to the page (administrator panel) where I can get the IP address of the Raspberry (important for configuring Putty, WinSCP and TightVNC). It's different for different router types so read what it says on yours (it says FunBox 2.0 on mine - a rather racy label if you ask me:) and Google. The router is also the thing you plug those 'Ethernet' cables into from the RPI and HDHomeRun.
Let me explain briefly what Ethernet is:
ether- Old French ether, from Latin aethēr (“the upper pure, bright air”), from Ancient Greek αἰθήρ (aithḗr, “upper air”), from αἴθω (aíthō, “I burn, shine”).
net- Middle English nett, from Old English net, nett, from Proto-Germanic *natją, from Proto-Indo-European *ned- (“to turn, twist, knot”). Compare West Frisian net, Low German Nett, Dutch net, German Netz, Danish net, Swedish nät.
As we can see, Ethernet means 'shiny twisted knot up in the air' (obviously).
It is important to change router settings so that the RPIs have static rather than dynamic addresses.
The IP addressees are stored in ~/.ssh/config - edit this file if they are changed