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?
Are you sure you are pressing the power button on the computer and not the monitor?

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.