I recommend to start with "Elements of Programming Interviews (in Java or Python)". It serves as a nice practical overview of the main algorithms and data struc

I recommend to start with "Elements of Programming Interviews (in Java or Python)". It serves as a nice practical overview of the main algorithms and data structures and when to use them. Personally I found it more complete than the usually recommended "Cracking the Coding Interview" while being equally approachable.