For a general description of DioNiSio, the techniques it uses, screenshots and samples you can read the article DioNiSio, a DNS Scanner (PDF format).
DioNiSio, from version 1.2.1, comes with DioNiSio man page. This manual page includes descriptions for its operation modes, options, files and some usage examples.
You can also read the DioNiSio README file. It explains how to build, install and use this program.
If you have any question no doubt to formulate it on the DioNiSio mailing list.