<<< I know I'll be able to share my internet connection by using a NIC card on the PC and wirelessly with the laptop >>>
If by this you mean that you can connect them both to a Wireless Broadband Router for internet access, then this does network them and you will be able to run File & Printer Sharing as well. There are no additional connections involved.
The Windows 98 PC will only be able to connect "wirelessly" if you install a Wireless Network Adapter (PCI card or USB), but there is no reason why the PC cannot connect by ethernet cable and the laptop wirelessly. They are still "networked".