I'm not a fan of painting the timbers: they will flake soon and look grimy. Just need to be sure the soil and mulch doesn't get too close to any wood framing. Can also run drainage pipe parallel with the timbers to draw water away from the house. In terms of installation it works well to drill 3/8 inch holes and drive 1/2 inch wide-two foot rebars in with a sledge hammer (FUN)! Say "Who's your daddy?" with each throw of the hammer.