When it has been determined at the election to provide for the erection of a free public library building, the board of trustees shall proceed to have plans and specifications of a public library building prepared, shall take bids thereon for the construction of the building and shall let the contract therefor to the lowest and best responsible bidder, and shall require of such bidder securities for the performance of his bid. The board may let parts of the material or labor for the erection of the building to different bidders, as to it may seem best, and may reject any and all bids.