how to configuring linux firewall and windows2000 settings

[Nelson Ivan]

Hi,

i'm reading some articles on internet about this and i feel a litle
bit confusing.

My problem is, i want a linux box to connect to internet, and use it
to setting up a firewall... and besides i want (for now) a windows2000
enable to connect to internet, also.
This is my schema:

|--------| |------!!-----| <><><><><>
|W2k +----------+Linux !! +-----CABLE MODEM-----( INTERNET )
|--------| |------!!-----| <><><><><>
firewall

After, when I'll use one more PC, i'm think to use a HUB to share the
internet between both PC's, and the schema seems like this:

|--------| |------!!-----| <><><><><>
|W2k +----HUB-----+Linux !! +-----CABLE MODEM-----( INTERNET )
|--------| | |------!!-----| <><><><><>
| firewall
|---+---|
| Linux |
|-------|

So, can anyone explain me what configurations do i have to do on the
firewall, speciallly about IPTABLES configurations. Also, i would like
to know how do i have to configure my W2k in first schema. I've tried
a few times, but i didn't get any results.

After that, I would like to know what i've to do when i'll use a HUB
to share the internet between both my computers. How do i set W2k
configurations and linux configurations.

Can anyone help me,
Thanks in adavance...
Nelson.