Questions about network layout

Hello all, thinking and reading of networks always make me think, and I have some questions, let me draw a sketch of the network I have, and then I'll put the questions:

[Internet]--->[Linux Bridge]--->[Windows 2003 Server]--->[D-Link Switch DES 1024D]-->Hosts

This is the big layout, now, the Linux Bridge has 3 NICS, two for making the bridge between the internet and the w2k3, and one for network management and squid.

The Windows 2003 Server handles DHCP and DNS, altough I don't like W2k3, this is necessary for the current IP Phone we have here that just don't work with the Linux NAT, so this is way this network is so messy.
Now for the questions:

1) The D-Link Switch is a basic 24 ports switch, is it possible to make for instance 12 ports on the switch to receive an IP like 10.0.0.0/24 and the other 12 ports receive 10.0.1.0/24? With Linux or Windows, really, I just want to know if it's possible. Remember that this Switch is a "dumb" Switch, does not have any administration on it.

2) Is it possible to build VLans with the Linux bridge? Or for this I would really need the Linux to actually handles DHCP et all?

3) Also, let's say we put a Wireless router, just to route internet and not intranet stuff.Eere should it be best? Right attached on the Windows 2003 with a different NIC to make a physical different connection, and then let W2k3 handle this, or on the Linux Bridge making it part of the bridge?

Please see that the Network layout can change (ie, putting the linux bridge as DHCP and DNS servers, and letting the W2k3 just for Active Directory et all), but it would be best if it didn't changes, because of the god forsaken Ip Phone that can't work fine with the Linux NAT.

Thanks a lot!!! :smiley: