Setting up my first Network

I have been given the dubious task of setting up a network for an organization that has few resources and even fewer persons capable of implementing them
Here are the requirements:
1. Must have three computers available at all times for students to open/ print word documents and surf the web.
2. Must rely on equipment at hand (even though it is extremely dated)
3. Must be as secure as possible (I know this is obvious, but I would feel really bad if someone commandeered these computers for less than honorable purposes)

Here is the list of equipment (Don’t laugh too hard)
1. Three Dell Dimension L433c workstations with 233MHZ, 128 MB, NIC
2. One Dimension 4100 1.1(?) GHZ, 128 MB, CD-R, Printer, NIC
3. One Netgear DS508 eight port hub
4. Will be adding WAP to serve other users wishing to access the cable modem service
5. Software:
Windows XP for the three L433’s
Windows NT for the 4100
Open Office
Here are my questions:
1. What is the best way for me to optimize this setup? I thought it would be best to connect the Netgear 508 after the Dimension 4100 so that I could masquerade the other three machines.
2. Is there a WAP that anyone can recommend with an integrated firewall? Hopefully, I could use this setup instead of passing through the 4100. (i.e. I could connect the modem>WAP>Hub>Workstations)
3. What would be the best way to secure this network? Obviously a WAP with a firewall would help greatly. What else do I need to know? I also imagine that I will have to issue a WEP key to the wireless users. How often should the key be changed?
4. Does anyone have any recommended links? I’m not averse to helping myself. However, I am an Undergraduate Engineering student and I already have a serious time commitment to my education. Not to mention the other tasks I perform for this group already.
5. How can I log the traffic on this network (I think this falls into the recommended reading category, but if there are any quick answers, I’d appreciate them)
6. I’m sure I am forgetting some things. Just throw in random comments/ suggestions/ heckling for good measure.

Thanks a lot for fielding my questions.
I appreciate the time everyone spends here helping others. I will try to contribute, but it appears that I am seriously outgunned here…
Thanks,