Home Network

I currently have a small home network. My Zyxel Prestige 643 I received with my COVAD 1.5/384 DSL. It has 4 ports. On those 4 ports I have 3 PCs and a Netgear 802.11b WAP. My wifes notebook connects via the WAP.

I was just given a D-Link 10Mbs Print Server which I was going to use on my network to share my HP Inkjet with. However, I'm obviously out of ports on my router.

So, my questions are the following:

1) Any suggestions on how I should expand my network with more ports? I want to avoid going to a wireless print server, since I was given this one free. However, that leads to another question.

2) Since my WAP is only an 802.11b, and the 100 light on my router is obviously not lit for that port - is my whole network running at just 10Mbs?? The 100Mbs lights are lit on the other 3 ports, but I've never tested the throughput on network activity to see what my throughput was. I had this debate with an acquaintance of mine and he insisted any 10Mbs device would slow the whole network down to operate at that speed. However, I always thought that was only the case on a wireless connection. IE, if you mixed G and B devices on a WAP, the WAP would operate at the slower speed for all devices in order for compatibility.

3) I was thinking of just adding a switch to the Zyxel. Something like an 8-Port D-Link, Linksys, Belkin, etc for under $50. Are there any limitations to this I should be aware of?

Thanks in advance for the input.