I have ugly dark barn board on the lower half of my basement walls in my rec room. Can you paint these and if so do you have to have special paint for this. I'm not sure paint would even cover all the crevices and nooks in the wood. Any ideas?

Any ordinary latex paint should do. Maybe what I do with concrete would work for you. Thin the paint way down and then apply as heavy as you can. This makes it easy to get paint down into all the low spots.

Personally I hate to see you do that. Somebody paid good money for that real wood, and once painted, it is gone forever. Perhaps try bleaching it first with just regular household bleach. If that is a disaster, you can still paint.