Even as a beginner, you should start to learn about the Chinese sentence structure. Using sentences as your base gives you the benefit of learning how to speak straight away. You will also be learning about how words interact within sentences.
Chinese language has very complicated grammar rules. There are general grammar rules followed by a long list of exceptions. Further, Chinese is a very precise language. Even when you use the same words, but in a different order, it could give a completely different meaning.
HSK 4B Grammar Workbook will help you practise how to form proper Chinese sentences with vocabulary that you are already familiar with. Even if you do not get everything correct in the beginning, you will learn from your mistakes and get better. This is definitely more fun than purely memorising the grammar rules.
We find reading will also help in your learning progress. You should check out the HSK Storybook series, which are also written with the respective HSK level words. Please go to www.allmusing.net to download sample chapters and audio files.