I'd say just watch some youtube videos, search for "litecoin mining" as far as I know there isn't really much that can be mined with only the CPU anymore, maybe something like feather coin. ASICs are miners you can plug into any computer, but it's a long story, just browse around the forums and look for videos.
You'll need a PCI-E Riser to mount a GPU, however since the R610 is a 1u server most GPUs will not fit. You'll want to mine CPU coins like Quark Coin, Primecoin, or maybe some others.