Today, cyber threats pose significant risks to governments, corporations and many other institutions as well as individuals. Tackling cyber threats requires planning and developing cyber defense strategy, enhancing Information Technology (IT) infrastructure, and more importantly managing human resources effectively. A key component in cyber defense is manpower, since it takes longer to train cyber defense personnel compared to conventional military branches such as infantry and artillery. Moreover, there is a scarcity of cyber human resources. Identifying, recruiting, training and retaining the cyber workforce necessitate a new and comprehensive approach. From the active cyber defense perspective, the cyber workforce should not have only defensive skills and capabilities, but also offensive ones such as detecting, tracing and counter-striking, mitigating and retributive counter-actions. This paper analyzes the areas in which an effective cyber manpower management needs to focus: recruiting, training and retaining cyber workforce as well as challenges and risks involved.