A welcome letter should include a personal introduction, a brief background of your qualifications and an overview of the class and your policies. It is important for parents to know right off the bat what your expectations are for the students.
Try to start your welcome letter with a statement of how excited you are for the year to show the parents that you care about being a teacher and are excited to work with their students. Follow that with an overview of the major aspects of the curriculum that you intend to cover for the year, including major assignments and any books you will be reading, if that fits into your content area. After covering the content, be sure to outline your classroom policies. This section should include your late work, homework, grading, absence and tardy policies. This helps smooth over any tough interactions you may have with parents about a student's grade or performance in class. Lastly, close the letter with another personal touch or an invitation for the parents to contact you whenever they have questions or concerns. Make sure your letter includes your contact information somewhere.
Welcome letters are a great way to make sure parents are included in their student's education, and they also help the parent feel more confident in the teacher's ability to effectively educate students.