Don't use it as a cutting board. Don't let stainy things sit on it. Treat it sort of like marble or other soft stones.
I have two wood-plank bathroom countertops, one Acacia and one vertical grain fir, because I'm a trendy idiot. Both stained and spar varnished so I don't have to worry about someone leaving a wet towel on them. I don't know if I'd top-coat in a kitchen where hard-bottomed stuff gets slid around, just oil is probably better.