The Internet teems with educational resources. Many websites offer lesson plans and activity sheets, some of which charge a fee for access. Sites that end in ".edu" or ".gov" generally offer quality information and ideas. The educational department of your state or province should have a website that includes publications on the curriculum requirements for the third grade. Curriculum publications include achievement goals, such as learning a certain number of vocabulary words or understanding certain mathematical or geographic concepts. You can base your lesson plans around these to help your third-grade student achieve better marks in school.
Most cities have educational or teacher stores that sell specialty educational books not offered elsewhere. Buying a selection of educational books geared specifically toward the third grade will save you a lot a time and effort coming up with your own lesson plans and activities. Many of these books have special copyrights that make all pages reproducible, so you can make copies for multiple students. Often educational books come in series or levels, which is helpful if you are tutoring a student for an extended period of time. They can also help you measure your students' progress.
Libraries are a fantastic free resource for tutors. Your local library should have an educational section. Many libraries offer online searches of their catalog you can do from home. If there are several branches in your area, ask if the library transfers books at request. You can also recommend books for the student to sign out on his own or create a reading schedule of novels from the library for the third grade, if he is struggling with reading.
Large book stores are increasingly offering specialized departments. Many book stores offer an extensive educational section with the latest in books for teachers, students and independent study. The children's section will also offer some hybrid entertaining/educational books for kids that you can buy and photocopy from or have your students buy. Used bookstores will have children's novels you can purchase cheaply to use in your sessions. Because they are already used, further wear-and-tear from many children borrowing them will not matter as much, and you can replace them more cheaply when they finally wear out.