(1) what measurements and what calculation would you need to make in order to determine the density of a rectangular wooden block?

(2)

recall that density is mass per unit volume, or

d = m/V
thus you need mass of the wooden block, and its volume,, to get mass you can use appropriate weighing scale and for the volume, you can measure its length, width and height since the volume of a rectangular solid (this is the geometry of the wooden block) is given by
V = L*W*H

hope this helps~ :)