Can I network two computers together to share a single internet connection?

[B.T]

Well here is the solution, but your question is not enough to answer.

1. If you have a wireless antenna to connect to your ISP
2. If you using WiFi Hot spot

Answers for N1

If you are using Wireless Antenna to connect to your ISP, you should have two lan cards. One for to connect to your Wireless Antenna and one for to connect to switch or hub.
And you should know the Ip address, Subnet mask, Default gateway and DNS to connect correctly to your ISP. In the network connections window make sure the Internet connection is using PPPoE. If yes share it .

Answer for N2

If you using WiFi hot spot you need wireless Router. After configuring the router connect two PC's to the router using standart straight ethernet cable.