I liked the book Basic Portuguese: A Grammar and Workbook by Cristina Sousa. If you’ve been learning for a while, you might want something more advanced, but it’s great for beginners because it’s informative without being overwhelming.
It focused mainly on the most common grammatical structures in European Portuguese. Irregular forms were discussed, but they didn’t go way into detail on every exception to the rule. They did a good job of keeping it concise (it’s less than 200 pages), while still adequately explaining the concepts and providing a lot of good examples. Each chapter has a few exercises at the end.
I remember it being particularly useful for explaining how contractions work in Portuguese (de + o = do, etc.).
It would definitely be a good starting point to spell out some of the grammar rules, especially in combination with all the great audio practice on Practice Portuguese.