Video-based coaching systems have seen increasing adoption in various applications including dance, sports, and surgery training. Most existing systems are either passive (for data capture only) or barely active (with limited automated feedback to a trainee). In this paper, we present a video-based skill coaching system for simulation-based surgical training by exploring a newly proposed problem of instructive video retrieval. By introducing attribute learning into video for high-level skill understanding, we aim at providing automated feedback and providing an instructive video, to which the trainees can refer for performance improvement. This is achieved by ensuring the feedback is weakness-specific, skill-superior and content-similar. A suite of techniques was integrated to build the coaching system with these features. In particular, algorithms were developed for action segmentation, video attribute learning, and attribute-based video retrieval. Experiments with realistic surgical videos demonstrate the feasibility of the proposed method and suggest areas for further improvement.