Thanks. WirelessG.... any color recommandation?Run down to Home Depot. Get a primer and finish coat in a color that suits you. Best to stick with latex. You will need a combination of low nap rollers and general purposes brushes. In the corners work the brushes and in the flat areas work the rollers.
Bob has a point about the polyurethane providing a more durable finish. I have 3 benches like this and I never painted or polyed them. I never saw the need. Why do you want to paint them? For looks? For protection?
I'd go with a clear satin or gloss polyurethane. That way you keep your "natural wood" look and poly is pretty resistant to most things you might spill on the wood so clean up would be easier than a latex painted finish that will scratch much easier. Color choice is yours if you go painted. I'd keep it light to help find dark things on the surface; downside is dirt will show quicker. Get dark and you'll have a tougher time finding that little spring thingey that popped out of something you are fixing.