Here is a list of all the resources, how to get them, and their rarity (items are listed from most common to rarest). For the rarest resources, it is best to request them from friends to get them:

From Rocks:
Blue Crystals, Pink Crystals, Gold Dust.

From Weeds, Bushes and Shrubs:
Smurf Berries, Weeds, Sticks, Pine Cones, Fern Leaves, Nectar.

Note: To get Honey Jars, supply your neighbor's buildings. To get Flour Sacks and Screws, supply your own buildings.