Q: I have an iPhone 3Gs and a wifi printer.   I do not have a computer or home Internet. Is it possible to create a connection with my printer somehow?

From the help article on airprinting:

The AirPrint-enabled printer must be connected to the same home Wi-Fi network as the iOS device. This is the default configuration in most home Wi-Fi networks.

So you need the printer connected to a computer with a home wifi network. How are you currently using a printer if you don't have a computer. What is it connected to?

Here is the full article on airprinting: http://support.apple.com/kb/HT4356

Actually and AirPrint printer needs to be connected to your wi-fi network wirelessly, not to a computer or to a hub or router using cat 5 cable.