Searching for means of developing an employee's skills?

Listen to them, and write a list for the top important skills that are needed to be developed. If you were able to find the gap or the missing skills, then you can look for the means to acquire these skills. 

Either by conducting workshops, training sessions, online training sessions, inviting experts. Sometimes, you can find that one of the team members had the skill, so you can encourage him to teach others. You may need to discuss this as well with your management and set some reward and recognition plans to motivate learning and developing new skills!