How do you paint a wooden fence?

Depends on how wet is was when installed. But on average we recommend staining after about 2 seasons of exposure.
Pressure treated wood may be painted. First, you need to figure out if your wood is ready to paint. Do this by putting a couple of drops of water on the spot to be covered, the wood is too wet to coat if it beads up, give it some time to dry. If the water is readily absorbed, you may begin to paint. You should use an oil-based primer and a high quality acrylic (latex) paint. If you prefer to stain it, purchase a high quality oil-based stain.