These are really nice switches to get given. Short of some technological breakthrough occuring that suddenly demands 1000BaseTX to the desktop, these switches will satisfy any home network for years to come. Or a small business. They are relatively small and lightweight too.

Networking 1.01.
You've probably heard of the OSI '7 layer' model. We're only concerned with layers 2 and 3 here. For reference, layer 1 is the Physical layer, that literally deals with how the bit stream is converted into electrical signals and moved from one place to the other. Layer 4 is the Transport layer, that deals with things like packet control and recovery, the TCP part of TCP/IP. We don't care at all about 5-7 in this discussion.

Layer 2 is the Data Link layer. This deals with converting packets of data into a raw datastream suitable for transmission by the physical layer. It also deals with MAC addresses, which are 'unique' hardware addresses assigned to network adapters. I quoted 'unique' because although by default every network adapter is set up with a unique MAC address that includes a manufacturer part and a serial number part, it is usually possible to override them in software. (In any decent OS anyway).
Layer 3 is the Network layer. This is the IP part of TCP/IP, where IP addresses live.

To try and clarify that all a bit further, lets 'demo' a couple of pings.

1) If you were to ping another machine on your network, your machines TCP stack ('Network'
- layer 3) would compare the IP address of the destination machine with your network IP address and subnet mask, and in doing so would realise that the destination was on the same network. At this point it would pass the packet to the layer 2 stack 'Data Link'. Assuming that you have just booted your machine and that it hasn't yet talked to the destination machine, you machine will send out an ARP discovery request, "arp who has destination_machine_IP tell my_IP". The destination machine will reply with it's MAC address, and then all intranet communcation will be handled layer2 <-> layer2 using MAC addresses only. Note that the destination MAC address will then be stored in an arp cache to speed things along in later communication.

2) Suppose instead that you ping a machine _not_ on your network. This time around when your machine compares the destination IP with its own IP address and subnet mask it will realise that the destination machine is on another network. Still in layer3, your machine will check it's routing table to see whether it knows about the destination network or whether it needs to follow the default route. Regardless, what it does next is essentially the same. It now sends the complete ping IP packet to the gateway or router that it just discovered. How does it do this? By using the same technique that it employed to talk to the local machine - It arps for the routers MAC address and then talks via layer 2 to it.

This is obviously simplified to hell, but hopefully should help you gain an understanding of what various network gear does.

A hub works only in layer 2. It simply rebroadcasts any layer2 communication to all the other ports on the hub, and monitors collisions. You can see why a hub soon gets flooded - if you have 10 machines on a 100BaseTX hub, then they have to share that bandwidth, ie 10Mbps each.

A 'domestic' switch is a bit more intelligent. It learns which MAC addresses are associated with each port, and only transmits data to the appropriate port. This means that (theoretically) each port could be communicating at 100Mbps simultaneously. Of course, in reality one of the ports is going to be a server or router connection that carries a large percentage of the data, but you see the point. Again, it only deals with layer2. It does not care 2 hoots about IP addresses.

A router typically deals in layer 3. It watches IP packets coming though it's ports, and routes them according to routing tables that have either been manually set up, or that have been discovered by automated routing protocols (such as BGP). It will have access control lists which will implement packet filtering based on IP addresses (simplistic firewalling)

So what do you have in you new gear?
You have a 'proper' switch. (Actually 2 of them). Essentially they do the same thing as a 'domestic' switch, operating in layer 2. But they have some really nifty tricks.
Firstly you can gang the Superstacks together. You need a 48port switch? You got it. You could add more (4 total = 96 ports IIRC).
You can tell the switch to lock down the ports to specific MAC addresses. If you're worried about someone installing a hidden open wireless router on an otherwise private LAN, this is useful.
You can segment the switch into separate VLANs. So you can tell it that ports 1-8 are on one LAN, and that 9-24 are on another. IIRC, you can define up to 16 VLANs on these switches. And you can VLAN across ganged switches obviously.
You can define ports as being important. This prioritizes their traffic over the switch backplane. Very useful for heavily used servers and routers.

One thing that these won't do is inter-VLAN routing. (Some big switches do). But who cares?

All the documentation for these is available here