Help with network design for Home & Home Office

[NetworkNewbie]

I want to set up a Home Office network in addition to my existing Home network and need some help as networking is not my thing at all...

Current Configuration:
- 2Wire 2700HD-G - DSL Modem/Router (4 ports, all 100mb) Provided by my ISP, currently all functionality except the DSL Modem is disabled.

- D-Link DIR-655 - (4 ports, GigE) DNS Forwarding, DHCP, Wireless n/g/b all running here using 192.x.x.x
-- LAN Port wired to 2Wire router
-- Port 1 wired to Win7PC1
-- Port 2 wired to D-Link DNS-321 NAS
-- Port 3 wired to HP Printer
-- Wireless n - Win7PC2, Win7PC3, DAP-1522
-- Wireless g - Notebook1
-- Wireless b - Notebook2

- D-Link DAP-1522 - Running in Wireless Bridge Mode
-- TV, PVR & Wii wired to this

- TrendNet TEG-S50G - Dumb 5-port GigE switch, not currently used

This is all running fine; however, I want to add a VMware ESX host that will house an office network (AD, DNS, DHCP, 3-5 servers with access to the internet), preferably on a different subnet (ie: 10.x.x.x). I was thinking about hard-wiring the ESX host to the free port on the DIR-655, but I'm not sure how to route traffic between the two networks. Ideally I would want anything on the 10.x network to get a DHCP address from the DHCP server on that subnet, while still allowing Wireless machines and my hard-wired PC to get their DHCP addresses from the DIR-655.
At some point in the future, I may want the PC's to become part of the home office domain on the 10.x network as well.

What would be the best way to do this and is there a better way to configure my existing home network?

 

[thiggins]

Why do you want a separate subnet? If you want both subnets to have Internet access, but keep traffic separate, you could just get a "Smart" / managed switch that supports VLANs and put the two groups on different subnets. See VLAN How To: Segmenting a small LAN - SmallNetBuilder