Now I'm using a router to connect my computer to the Internet. I installed VMware Workstation 7 on my computer and installed a guest OS which is CentOS 5.3. Now I want to using putty to connect to the guest OS in my host computer, and I need the guest os can access the Internet too. How can I configure my host's network, guest os and my router? I have little knowledge about network, can you guys give me a step by step direction or something similar? Great thanks!
Setup vmware to use bridged networking. Your host will get an IP address from your router, and your VM will get a separate IP address from your router. Setup SSH port forwarding on your router to point to either your host or your vm. You can then ssh into the box you're forwarding to, and ssh into the other box from there. Another option is to run ssh on port 22 on one of your boxes, and a different port on the other. Port forward to both of them, then ssh to the port that matches the box you want.
Another option is to install the open-source dd-wrt firmware on your router (if supported) and run a VPN on the router. (This is complicated, only supported on some routers, and could potentially brick your router, but is cool stuff.)