[jem]

Bit of an over simplification but 802.11g is one of a set of wireless data transmission (WiFi) standards, equipment which conforms to this has a maximum (theoretical - you'll never actually get anywhere near it in real-life) data transmission rate of 54 Megabits per second. There is an older 802.11b standard and a more modern 802.11n which can work at a higher speed.

Generally routers are downward compatible so a 802.11n capable model can also be set to work with equipment which is 'g' and even 'b' only.

In your case you have the cable modem (the EC8C007) which connects to the cable feed but this has no routing functions or wireless ability, it can only connect one device at a time to the internet. So the output of this is connected to your routers WAN connection and then you can connect four devices wired to each of the four LAN ports on the device and all of them can use the internet at the same time.

As this router also has wireless capability, then as you have discovered, you can connect devices such as the Kindle to it as well without needing a physical wired connection. You should find that the PC will still work while physically wired in but if you wanted to be able to connect the PC wirelessly it would need to have a wireless card installed in it or some kind of USB wireless dongle. Personally I wouldn't bother, generally speaking wired connections are more reliable anyway.

In the future, if you wanted to upgrade your internet connection speed, then VM would supply you with what is called a 'SuperHub' which is a modem and 802.11n wireless router combined and would replace both of your existing devices. If you look through some of the threads here you will see that there are quite a few 'opinions' (shall we say) as to the quality and suitability of the SuperHub though. However when and if the EC8C007 is replaced or dies, you won't have a choice, it'll be the SuperHub or nothing.