Guys, do you think it's okay to use my somewhat-ancient computer to mine for Bitcoins? It's got hardware that was great a few years ago, and an Nvidia graphics card... Might it work?
Go ahead and start mining with that... get into one of the pools, figure out how it all works now before you go out and spend some real money on some ATI 5830's or whatever you can find that works well and you're comfortable paying for.
Use this chart to help you pick the best card for you
https://en.bitcoin.it/wiki/Mining_hardware_comparisonAnd yeah.. you're not going to want to bother with CPU mining or nvidia mining longterm.. but nothing wrong with trying it out for a couple hours to get the hang of how everything works.
Welcome to the fold!
-lowlevel