Thank you for your question!
In most public schools, teachers do not officially start grading until around 3rd grade, because this is when the students must start taking the state standard tests. As the teacher, you can make the decision on how you grade any given test. A worksheet can be difficult to grade, particularly in the earlier grades, because there aren't that many questions in the test to begin with.
I think daily work does not necessarily need to be graded. But I do think that the chapter reviews should be graded in some way, even if you decide to do a pass/fail type grade. Obviously the purpose of the test must be considered when you are grading the paper. For example in handwriting, you are clearly grading the child by his neatness and letter writing. However, if he is taking a math test, you would want to grade the child more on answering the questions correctly, than judge him by his penmanship.
When creating the portfolio, you would want to submit examples of your child's best work. By best work, you would include the child's neatest handwriting assignments, his math papers with the most correct answers, or his best English compositions.
Over all, it is important to remember that the purpose of grading is more for your benefit, so that you can see what your child has or has not learned. The tests are a great asset to you, when assessing your child's learning levels.
God bless you and your family!