Many say that after a heading there's no need to indent because the heading makes it clear. However, this isn't a hard and fast rule and some do. Newspapers tend to indent because of the column width- it makes it clearer. If you look hear, you'll see that different people approach the issue in different ways:
I think as a basic guide, try to make it clear. In writing, I tend to leave a space and not indent.
- For Teachers