The simplest thing that you can do is buy yourself a cable router like
this one.
The set up is simple:
1. Plug your cable modem in the WAN port.
2. Plug both computers into the other ethernet ports.
3. Follow the instructions for the router configuration. This will probably have you set your PC's IP to DHCP (your router should also serve as a DHCP server) or a static value that the router is already configured for and its default route to the router's LAN IP. Write down all of your cable modem's IP addresses (local and public, DNS, etc.)
4. After the PC has been configured, log on to the router using the accompanying CD or by connecting to its web server (probably
http://192.168.0.1 or
http://10.10.0.1). Provide the connection characteristics of your cable modem to the router (those you recorded earlier).
5. Test your Internet connection from your PC.
6. Configure your Sun system so that its network interface uses DHCP.
7. Test your Internet connection from your Sun system.
That is it. Now you have a simple and very functional network.
Consider carefully your choice of routers. I picked a wired (i.e. not wireless) Netgear 4-port router/switch. It has a built-in firewall and DHCP server. I have something similar to it at home but with more ports. You may want a wireless router, which still has physical ethernet ports. You will want to enable the security features if you use the wireless capabilities. The final consideration that you may want to make is with regards to VPN. If you would like to connect back to your home network from work, you may not want to get a Netgear product. Their VPN server (at least with regards to my model) requires their VPN client (I'm too cheap to pay the extra money for it). Other than the VPN, I am very please with the Netgear products. I have used Linksys as well with two bigger downsides: 1) two different wireless access points burned out, 2) the same units both had inferior signal strength to my other Netgear wireless router).
I hope this helps.
Thomas