Where could I find Peercoin's documentation? The whitepaper hosted in the official page is pretty lacking in "whys" so, is there anything that resembles https://bitcoin.org/en/developer-guide with Peercoin? Any technical papers?
Peercoin's code is based on Bitcoin's code. We started a Wiki to document the differences. This Wiki can be found at this address: https://wiki.peercointalk.org/index.php?title=Main_Page

You can start with the block structure for example: https://wiki.peercointalk.org/index.php?title=Blocks

We do not have any technical paper apart from this.