I believe very strongly that all children can learn. It is the duty of the teacher to discover each students learning styles and to find a way to incorporate those learning styles into every lesson.
Students also have to know that what they are learning is relevant to them. If they do not understand why they need the information you are teaching them, then they will not be as interested in learning it. Students need constant links between what they are learning in school to what they are doing in their homes with their family and friends.
Often, what is provided in the teaching manual is not sufficient to meet each students needs and provide them with relevant, student-centered instruction. The textbook makers do not know my students, I do. Only the classroom teacher can make lesson and textbook adaptations to meet the needs of every student.
When I begin to plan a lesson, I use the teacher manual as a guide for the overall objectives of the chapter or lesson we are working on. I will often look at their suggestions and may use them as a basis for my lesson, but never as the lesson itself. Once I have an idea of what I want to teach and some ideas on how to teach it, I often go to teacher sites on the Internet for some more exciting and relevant ideas. I also ask other teachers what they have done. Before I take that lesson into the classroom, I want to know that it is going to reach each one of my students in some personal way.