Measure up from the floor with a tape measure and make a pencil mark on the wall at the height you would like the shelves to be.
Place a 4-foot level on each of the pencil marks in turn. Draw a level line along the bricks with a pencil
Hold a wall shelf bracket up to the end of the top line, matching the top of the bracket with the line. Mark the screw hole locations onto the wall with a pencil. Move the bracket 2 feet to the side and mark the holes again. Continue until you've covered the entire length of the planned shelf. Repeat with the lower shelves.
Drill a hole into the bricks at each of the marked hole locations with a drill and masonry bit. Place a masonry anchor into each hole and tap it in firmly with a rubber mallet.
Place a bracket up to each set of holes and screw it into the wall with screws placed into the masonry anchors. Repeat until all the locations have brackets.
Place shelf boards onto the brackets.