Introduction to Hindi Grammar - Watch this video to understand the basics
This Grammar Book with 14 Lessons includes links to the audio that matches the Lessons. The links are embedded within the pdf book
Sentence Builders - These worksheets give you handy charts for learning new vocabulary and how to put them into sentence with correct sentence order.
Here's an online Grammar book with 137 lessons. You can go directly to the topic you're wondering about, or follow the course in order.