home network - how to ???

[HyperUniverse]

Hi,

I want to switch my home network from Windows Server 2003 - XP, to Debian Lenny.

There is a Server (Debian Lenny), with wifi internet and lan (eth) network that goes into a hub.
There is a Desktop machine (Lenny) connected to the lan (hub), via eth.

After I successfully configure these 2 machines, there is going to be another desktop connected to the network via eth.
And a laptop, probably via eth also.
But for now I want to make the first 2 machines work together.

The server is there to provide:

• internet access
• file sharing
• printer sharing
• home folders for each machine connected to network
• backup
• cctv surveillance for the property

So the problem is this:
My Windows network already works perfectly as I said above.
After I installed Lenny server (with file, print, dns) how do I configure it to make it work ?
I have read lots of tutorials how to do all these things I want, but either I am too stupid, or they were written for older systems and they do not work on Lenny.
My Lenny desktop connects to the internet through the Windows Server 2003 with no problems at all.
But if I put the Lenny Server, then the Lenny desktop has no access to the internet at all, and it connects to the network with a "self-given ip address" (or something like this).
Worth to mention that the Lenny server IS connected to the internet via wifi.
Do not ask me if I have configured anything else on the Lenny server. Cause I have messed with it so much (following instructions from other forums), that I had to re-install the system just about 5 times.
Now it's again a fresh install.
And I said: That's it! I'm stupid! I need help!
So, please help me to:

1. dns, nat, or whatever I need, so when I connect a machine to the network (even a guest machine), it will have internet access,
2. move home directory from local machines to the server,
3. create back-ups for machines, preferably a back-up tool that works even if Linux is not working anymore (I'm very good at killing it).

File and printer sharing I have succeeded some time ago, so I would probably be able to do it again.
If I move home from client machines, to the server, and the server is not up and running at some point, do I still have the files from home on my local machine? Same question for the laptop. If I move home from laptop to the server, when I take my laptop away from the server, do I still have all my files in home directory?

Thank you.

[rcgreen]

First, Internet access.

This tutorial will go over all the steps one must take in order to set-up routing on a Linux box. There are some minimum requirements you must have in order to follow this tutorial to its completion. First you need a PC with Linux on it, the examples I will be giving are based off the Ubuntu distribution, but my examples should work on most other Debian based distributions

HOWTO: Ubuntu internet router: IPTables,DHCP,DNS,& IP Masq - Ubuntu Forums