At least seven people I know have paintd over existing paneling, so Idid too. Our consensus of opinons would be to wash paneling as you would any wall, let dry well. Prime with a good grade of primer, then paint. None of us removed the grooves, this might be a cosideration for you. There is a product at wallpaper stores that covers uneven surfaces such as cinderblock or cracked walls, you could take a look at that. I must say that the paneling without grooves removed is very satisfactory to all of us who have done as above. Good luck!