I have found many things that were great resources. There are some I use everyday for my third grade class.
I recommned websites, because honestly I print off these worksheets.
commoncoresheets - is good for math practice pages and spelling word finds. My students find these pages to be fun to work on during centers or after a test.
mathaids.com is another good website for multicipliation sheets. I use these to test my students on their math facts. There are many options to choose from so you can print out the test you need.
classdojo is another website I use for behavior. The students earn points when they complete homework and if they come to school on time. They earn these points throughout the day.
Iready workbook - the book I use the most for reading comprehension is awesome. There is so much information in the book and it is very organized.