Your child's classroom is waiting for a mom like you. Run, don't walk, to the phone and make an appointment to meet with your child's teacher. The sooner you meet, the sooner great things can happen. Many teachers would love to do more projects and creative activities, but time is almost always the limiting factor. Meet with the teacher and ask if there is anything you can do to help supplement lessons with fun activities. Be very specific.
For example, if the children are reading stories about friendship, suggest that you could come in and help the children write their own stories about friends and make them into little books with illustrations. You could assist the teacher by helping students with writing and illustrating while the teacher works with small groups of students.
If you are interested in math, suggest to the teacher that you could facilitate a game in which students play "store" after a lesson.
Remember that it is very important to keep any commitment you make to assist a teacher. Teachers get very frustrated if a volunteer plans on doing an activity with the class and then doesn't show up.