Is there any version of Linux that you can use a wireless internet/network configuration with? I have tried Fedora Core & nothing works... i'm stumped on any other choices... any suggestions/comments?

You can use wireless with Fedora Core.

If nothing works, then maybe there are some issues with your computer..
Is it plugged in? :p
Are you sure you are pressing the power button on the computer and not the monitor? :p

Is that the button that says "off"? lol j/k

everything works fine for my wireless setup on windows, but nothing on fedora core... what other issues could it be?

99.999% sure it's a driver issue, but since you haven't told us what kind of wireless adapter you have it's a bit hard to help. I've never had problems with wireless in linux - but I know a few people who have with certain hardware.

I have a Linksys WRT54G router & a D-Link PC Wireless card (not sure of the model on the dLink)

I have a WRT54G & linksys wireless B card working in arch linux using ndiswrapper, the arch wiki is very informative. Check out http://www.linuxcompatible.org/compatibility.html and search your card make/model.