Hud rental program? I think any hud "rental program" and section 8 would be one in the same. But as far as I'm aware, hud does not own any rental homes.
In terms of how section 8 rules work, I would recommend going to your county/city section 8 program and getting their landlord rules/laws. Every county/city administers section 8 a bit differently. Some require you to get your inspections before you get your tenants. Others require the tenant first and then the inspection.