When performing software change tasks, software developers spend a substantial amount of their time navigating dependencies in the code. Despite the availability of numerous tools to aid such navigation, there is evidence to suggest that developers are not using these tools. In this paper, we introduce an active help system, called Spyglass, that suggests tools to aid program navigation as a developer works. We report on the results of a laboratory study that investigated two questions: will developers act upon suggestions from an active help system and will those suggestions improve developer behaviour? We found that with Spyglass we could make developers as aware of navigational tools as they are when requested to read a tutorial about such tools, with less up-front effort. We also found that we could improve developer behaviour as developers in the Spyglass group, after being given recommendations in the context of their work, navigated programming artifacts more efficiently than those in the tutorial group.