People often ask appropriate practice and revision materials for the SATs in May. There are a lot of really good resources out there which are easily accessible. Just make sure they are up to date for the current curriculum and relevant for KS2. Here are a few examples:
CGP Maths SATs Revision Guide
CGP English Study Book - useful for grammar revision in particular.
CGP Maths SAT Buster Practice Tests
Letts KS2 Comprehension Practice Workbook