Before you start writing a module, ask few questions:
1) Is there any similar module that will work for me?
If you can find a similar module maybe you can contribute in developing/ bug fixing that module instead of writing a module from scratch. for example there is a lot of content, gallery and download modules in XOOPS which you can use and develop more or customize for your needs. honestly i see no mean to write any more content module in XOOPS.
2) Is there any similar functionality in other modules which I could copy and use.
Maybe it seems odd but it will be good to announce in https://xoops.org forums about your future plans for a module and your needs. Please explain what you want to do. Usually there are some modules with similar functionality which you can use in your module.
If you didn't find any module that would address you need, and you decide to develop your own module, we hope that this document will make it easier for you.
Please let us know if this Module Developer Cookbook was helpful, and if we could improve it.