Whenever the governing board of any such corporation shall deem it advisable to issue the negotiable coupon bonds thereof for any authorized purpose, such governing board shall provide therefor by ordinance or resolution, duly passed and adopted and spread at length on the permanent record of its proceedings, which ordinance or resolution shall specify and state the amount and purpose of such proposed bond issue, the ultimate maturity of such bond issue, and that the annual bond maturities thereof shall be payable in accordance with the provisions of this act. If such issue will create a new debt the object thereof must be stated; and if the purpose thereof shall be the funding or refunding of an existing indebtedness, such existing indebtedness shall be described sufficiently for identification and all bonds, warrants or other securities thus to be funded or refunded shall be described by setting forth their identifying numbers, dates and amounts and the fund or funds out of which the same, according to their terms, are payable; and said ordinance or resolution, or a subsequent ordinance or resolution which shall be passed or adopted before or at the time of incurring such bond indebtedness, shall specify the provisions to be made for the payment of principal and interest of such bonds and also to constitute a sinking fund for the payment of the principal thereof within thirty (30) years from the time of contracting such bond indebtedness as required by law: provided, that where such bonds shall be required by law to be authorized by an election upon the question of the authorization thereof, the ordinance or resolution providing for and calling such election thereon shall comply with the foregoing provisions and requirements of this section in the ordinance or resolution. The governing body of the issuing corporation shall prescribe the bond form and coupon form by ordinance or resolution at any time prior to the delivery of such bonds to the purchaser thereof.