I would like some help with my small business network.

I am in charge now of our computer network, due to a tight budget Im left with finishing what someone else started. Im first wanting to verify if things are correct so far before continuing.

This is a small business with 2 locations. 1-office, 2 warehouse.

Office has:

comcast modem, cisco router, switch, then 3 servers, 5 pc xp and 7, 3 printers
LAN 10.10.20.1 Subnet 255.255.255.192
Servers running SBS 2003
SVR 1 DC/DNS/DHCP/Exchange
SVR 2 Webserver/WSS 3.0
SVR 3 BDC/BDNS/WSUS


Warehouse has:
ATT modem, cisco router, 3 pc win 7, 2 printers
LAN 192.168.1.1 Subnet 255.255.255.0

There is a vpn tunnel between the 2 cisco routers


1. Is there and reason for the 10.10.x.x address for the office vs 192.168.x.x??
2. I can map a drive thru the tunnel but cant "see" the network on each side
3. The office network seems very slow, slow to print, slow to browse is there anything I should be looking at 1st

1) Yes and no. This segments network traffic. Depending on the size it may not be needed but it is a best practice. Though, I would have stuck with the class A 10.x.x.x network.
2) What do you mean "See"? If you are browsing through your local computer you would likely be confined to your immediately network or VLAN. You should be able to ping, etc. I imagine that would be sufficient to do any work.
3) You will need to determine the route a computer takes to surf the web and print. Where is the printer/print server in relation? What is the comcast network speed? The cisco router could be limiting browsing speeds over port 80, for example, if business demands outweigh surfing the web.