From the Mises site:
Lessons for the Young Economist is easily the best introduction to economics for the young reader—because it covers both pure economic theory and also how markets work (the domain of most introductory books).
Robert Murphy has the right frame of mind and mastery of the subject matter to provide the best possible pedagogy. The logic is super clear. The organization is impeccable. It achieves a great balance between “plain old” economics and that aspect of economic thought that is considered particularly Austrian. Therefore, it prepares the student for both conventional economic studies in the future and provides the logical rigor and policy clarity that only the Austrian School perspective can offer.
From Mises.org: Many more can be found here: https://mises.org/library/books