Making rental properties into a business.

Hello! Can someone point me to a podcast, book or blog post about how to run your rental properties as a business. How do we know we qualify and what are the steps? We own two single family rental properties and an ADU in our back yard. I am not sure this qualifies. We do have an LLC created. In addition, my husband does some side work doing landscaping, installing turf, etc. Is there a way to group the rental properties and the work he does in turf/landscaping all under the same business?