I don't have much in the way of security issues because I don't allow external connections (outside of my LAN).
To get to your work computer from home, you'd need to get your IT department to open up a port in the firewall unless you have your own external IP (unlikely, and also unlikely that they'll be willing to open up a port for you unless it's a very small company).
To connect to home from work you just need to follow these instructions in forwarding a port through your wireless router.
My office is very small, basically I'm the IT guy because I know more about computers than anyone else here. As I see it, our internet comes in from the DSL modem goes to a wireless router to a switch to out individual computers. The switch gives out the IP address. again thanks for the help
Yes, this is the way to go or you can buy a router with a VPN server and you don't have to do anything as long as nobody on your LAN wants to middleman your VNC session and steal your info in transit If you have a VPN you can also use RDP which in the current generation (6) is now more secure than it use to be but you need current RDP on both client and server. Any remote access protocol that is only encrypted can be middleman'd if its not authenticated (prior to RDP 6 there was no authentication)
If you want to pay for a service (from Citrix), Gotomypc usually works even with firewalls in place as it routes over port 80 or 443 and its secured using SSL w/128-bit AES.