First you need a budget, then cameras, microphones, lights, weatherproofing to fit the budget. Minimum requirement for a budget camera for what you are doing is to have a mic jack. Then you need a mic and, since you will be outdoors, that too will have to be on the hardy side. If you are more than a couple feet from your talent, if you have talent, you will probably need a wireless mic. otherwise for pictures of work processes you can capture the ambient sound and narrate over top in post.
