The board shall, subject to the limitations in this Article, establish by-laws, rules and regulations, which shall have the force of ordinances, for the proper maintenance of a uniform system of discipline for both employees and pupils, and for the entire management of the schools, and may fix the school age of pupils, the minimum of which in kindergartens shall not be under 4 years, except that, based upon an assessment of the child's readiness, children who have attended a non-public preschool and continued their education at that school through kindergarten, were taught in kindergarten by an appropriately certified teacher, and will attain the age of 6 years on or before December 31 of the year of the 2009-2010 school term and each school term thereafter may attend first grade upon commencement of such term, and in grade schools shall not be under 6 years. It may expel, suspend or, subject to the limitations of all policies established or adopted under Section 10-22.6 or 14-8.05 [105 ILCS 5/10-22.6 or 105 ILCS 5/14-8.05], otherwise discipline any pupil found guilty of gross disobedience, misconduct, or other violation of the by-laws, rules, and regulations, including gross disobedience or misconduct perpetuated by electronic means. An expelled pupil may be immediately transferred to an alternative program in the manner provided in Article 13A or 13B of this Code [105 ILCS 5/13A-0.5 or 105 ILCS 5/13B-1]. A pupil must not be denied transfer because of the expulsion, except in cases in which such transfer is deemed to cause a threat to the safety of students or staff in the alternative program. A pupil who is suspended in excess of 20 school days may be immediately transferred to an alternative program in the manner provided in Article 13A or 13B of this Code. A pupil must not be denied transfer because of the suspension, except in cases in which such transfer is deemed to cause a threat to the safety of students or staff in the alternative program. The bylaws, rules and regulations of the board shall be enacted, money shall be appropriated or expended, salaries shall be fixed or changed, and textbooks, electronic textbooks, and courses of instruction shall be adopted or changed only at the regular meetings of the board and by a vote of a majority of the full membership of the board; provided that notwithstanding any other provision of this Article or the School Code, neither the board or any local school council may purchase any textbook for use in any public school of the district from any textbook publisher that fails to furnish any computer diskettes as required under Section 28-21 [105 ILCS 5/28-21]. Funds appropriated for textbook purchases must be available for electronic textbook purchases and the technological equipment necessary to gain access to and use electronic textbooks at the local school council's discretion. The board shall be further encouraged to provide opportunities for public hearing and testimony before the adoption of bylaws, rules and regulations. Upon all propositions requiring for their adoption at least a majority of all the members of the board the yeas and nays shall be taken and reported. The by-laws, rules and regulations of the board shall not be repealed, amended or added to, except by a vote of 2/3 of the full membership of the board. The board shall keep a record of all its proceedings. Such records and all by-laws, rules and regulations, or parts thereof, may be proved by a copy thereof certified to be such by the secretary of the board, but if they are printed in book or pamphlet form which are purported to be published by authority of the board they need not be otherwise published and the book or pamphlet shall be received as evidence, without further proof, of the records, by-laws, rules and regulations, or any part thereof, as of the dates thereof as shown in such book or pamphlet, in all courts and places where judicial proceedings are had.