There are a few steps you should take to prepare to paint your board and batten siding. They include:
Clean the wood and remove any debris from it.
Make sure the battens and boards are tight.
Apply the primer coat with a paintbrush or paint sprayer.
Caulk the edges of the battens.
Apply the top coat of paint with a paint sprayer. When the paint dries, add an extra coat to finish the job.