If I understand it correctly, blocking stats stack like other equipment stats. For instance, the block armor of your weapon and shield add up to determine total block armor. Parry amount would be calculated separately on weapon and shield before being totaled.

Wood gear is pretty bad. It's better than nothing, but next to bronze gear, it's garbage. Luckily, a bronze buckler is not too hard to make and is a parrying BEAST.

For my playstyle, I have found blocking to be not particularly useful. Tower shields are tailor-made for blocking, but they are heavy and cumbersome (-20% move speed). Blocking still consumes stamina and raises your stagger bar, but you don't get to stagger your foes for the damage bonus. Blocking cannot prevent as much damage as a well-timed parry with an equivalent round shield or buckler.