Once you get a Dev Board, and the miner (like the one I mentioned above) to load in the board, you are all set.

The dev boards comes with usb and power adapter.
The software to program the board comes along in a CD on you can download the latest versions, that is not an issue.

If you are going for fun and to discover new things, even one DE1 is enough (although it can do only 3.10 MH/s). But you can learn things.

I was able to compile an optimized version, which runs at 12MH/s but all works are rejected, so I am no sure how much can this little boards give back.