The Tabular engine underpinning the Power BI data model is largely model agnostic. Anything that can be represented well as a series of tables and relationships can function with the engine.
That being said, for ease of use and and consumption by end users, a dimensional model is far and away the best. I truly don't know of any better resources than the Kimball dimensional modelling books. If you're serious about building good models, you should read these. There are some things that I don't agree with the Kimball group on, but as a foundation, they can't be beaten.
Another worthwhile resource to check out is powerpivotpro.com, especially the archives, as some of the older posts would really dive into tactical design tips for the Tabular model. I don't find the site to be a good resource for general dimensional modelling, as that's not the goal. The goal is to advocate for Power Pivot and show value in specific business scenarios. If you can find an example that maps well to your own domain, then it is very helpful.
Another great blog worth reading is sqlbi.com. They cover some of the best modelling and design patterns specifically for DAX and Tabular.
