How should I insulate my shed to avoid mold and mildew?
I think the key thing is to use a quality house wrap made for the concrete/fiber lap siding. Concrete fiber siding will transfer moisture much more readily then wood, vinyl, etc. Products like DuPont DrainWrap (essentially their standard house wrap thats corrugated) will allow for air movement and water drainage. There are a lot of other products that employ similar techniques but the key is to make sure there's breathing room between the siding and sheathing.

Also, the wrap should be stapled using caps and taped per the manufactures specs.

For the roof I would look to high performance sythentic underlayments and ensure you have adaquare venting in your eaves