The Guide to the 3rd Grade - this site goes through the things that your child will be learning this school year, and some activities you can do with him/her to benefit his/her learning.
Homework Help for Grade 3 - this web page offers different articles for parents of third graders to help them with homework time.
Khan Academy - this site offers supplemental resources and videos that break down the math and lessons your child is learning in class. This can be used for your child if they need additional help, or it can be useful for parents who are trying to help with homework.
Improve Reading Comprehension - this article gives suggestions of different things parents can do to help improve their child's reading comprehension skills.