The title mentions local grants because they are by far the easiest to get. Having read and graded federal grants, I found that they were so professional they put amateurs like me to shame. PhD's from major universities write most of them and usually involve a district as a whole or a study that will benefit education in the future.
Local companies, national companies, school districts, teacher organizations, etc give grants. Keep your eyes open for opportunities that come through your hands. I found that many I received, I received from the same place year after year.
Having said that, during my years of teaching I received close to a hundred local grants totaling thousands of dollars for my classroom and my school. I found teachers hesitant to apply thinking that it was much too difficult to do. It isn't; it's really quite easy following a few simple guidelines.