That would depend on what you're trying to accomplish and who you are as a manager and individual. Off the top of my head I can tell you that Podio, Asanna and Basecamp are all popular project management tools. Which one you use really depends on you and the features you want. On a personal level I use Trello which I make work for me. It has the features I want and allows me to display information that seems logical to me. I suggest that you play around with all them and find which one works best for you. If I'm off the mark and you're asking about a specific system I suggest scrum. Although scrum is most talked associated with building agile products I've successfully used it on a wide variety of projects technical and non technical.
Hope this helps and best of luck!
Easily without a doubt the best 2 product management tools I have used are
www.perfectcloud.io which allows you complete oversight of application use and data flow paired with a next gen cloud encryption system.
The other is www.mycrowd.com which allows you to oversee teams and objectives seamlessly from a single interface and to source freelancers from all the major providers for tasks your team is unable to meet.
Every project has 3 aspects which require tracking: budget, timeline/progression and communications. In other words, you need to be aware who, what, when. For budget I usually use Google Docs, which allow pretty complex calculations and even collaboration. The original PM tool has always been MS Project, which can actually do all of the above. Recently Basecamp has become very popular, I personally prefer Trello due to it's more visual way of handling tasks. For software related project, you would want to know Jira, which is a bug reporting tool.