The most common types of wood to make a shelf out of are Pine, for its affordability, Plywood, for home made shelves, Cherry, because it is light weight, and Mahogany because it is elegant.
Pine.
get 3 pieces of wood and nail them together
Making a floating shelf is easy. All you have to do is find old wood and place then on the place with screws.
There are numerous places to purchase wood shelves. You could go to a wood craftsman and by a wooden shelf there, or buy a shelf from Amazon or Ebay.
It depends on the length of shelf you desire. For a longer length of shelf a hardwood like maple would be best. For a shorter length shelf balsa is more than satisfactory and rather cheap.
oak is the most common I know
coal, methane, wood, biogas
One can make a pot shelf or rack in many different ways. The easiest way would be to get scrap pieces of wood and put them together in the form of a rack.
Shelf Fungi grow on dead wood. In rare cases, it grows on live wood, and starves the tree from all of its nutrients.
normal wood
WOOD
hickory, maple, oak