Always buy "certified seed". This is identified by a blue tag saying certified. By spending a few extra cents up front, you will save many hundreds of dollars along with the added aggravation of controlling unwanted weeds later. Choose the right grass seed, sod or sprigs for your situation.
Saw blades should be stored separately. Keep each blade secured between two pieces of plywood, fastened together by a nut and screw that goes right through the center of the blade. Blades that are chipped, bent or in any way damaged are discarded at once.