You can find some useful tools, links and community resources below:

Blockbench - https://www.blockbench.net, https://www.blockbench.net/plugins/hytale_plugin 

The official tool for creating models and assets for Hytale, with a plugin to integrate easily within the game.

Hytale Modding Wiki (TBC)

This knowledge base offers up-to-date information on mod creation and tutorials, contributed by a team of experienced developers and authors.