> Where can I find an article explaining how to connect a win98
> machine to an xp machine which is sharing a firebird db.

This is an standard client-Server Setup. Install the server on the XP
machine, and the client on W98.

> I need to know the minimum files needed plus to configure this.

Most you need is the fbclient.dll.

> The app will be using an ole provider on the win98 machine.

Read the install-notes for that provider too.

Elmar