Firstly, document a plan and supporting procedures for how you will:

supervise the acceptance of each delivery (i.e. for the timber, steel and concrete deliveries, assuming they may all occur at the same time)

ensure safe handling of the materials - consider in particular any risks of damage during transportation and what you can do, in the event of the goods arriving damaged

ensure the materials are stored safely and correctly on-site until ready for use

communicate these procedures to relevant personnel including what to do should there be defects in materials through incorrect installation.