Networking :: Connecting To Internet With Lubuntu Through Ubuntu Machine

How to create some sort of network, which would mean that one computer (Lubuntu in this case) is connecting to internet through second PC (Ubuntu), which is directly connected to cable, so maybe I get some manuals and tips. The computer which is connected to internet have two LAN cards (Realtek 8139 and integrated nVidia MCP65), Realtek card is connected to the internet provider cable (internet is tied to my computer's MAC address and uses static IP).

Second computer have also a Realtek card and it's connected to first computers integrated card. Anyhow - I've put on the first computer eth1 (which is integrated MCP65) IPV4 setting to "Shared to Other Computers" and IPV6 to "Link-Local Computers" and while I was having Windows XP on the second machine, setting on it (the XP machine) DHCP (or how was it correctly called, when system automatically resolves or gets the IP and the rest what it needs?), second computer was receiving Internet signal and I could use both of them in such way.

Now the second computer is with Lubuntu and I thought that I could do the same way as did on XP - just put in Network Manager for the connection (eth0) everything to automatical and there will be internet, but there aren't and the manager shows some kind of "Automatic Ethernet" option, which after activation also doesn't do anything. What do I have to do, to make my Lubuntu machine to recognize Ubuntu's eth1 and to use it as a source for Internet?