Having made the decision to allocate a portion of your portfolio to trading gold mining stocks, the selection process can be somewhat daunting when confronted with the hundreds of available companies to choose from. All of these companies possess projects that are at various stages of the development process. As projects make the progression through the Mining Life Cycle, they become more valuable (assuming everything else remains equal). By choosing companies with promising development potential, you can increase your chances of success and substantially reduce the list of available candidates (See above for details).
For a powerful tool that will enable you to search specifically for gold and silver stocks with development stage projects I encourage you to visit GoldNerds. Every company is classified according to the development status of their respective projects. The three classifications are Producer (P), Developer (D) and Explorer (E). A detailed description of each of the projects is also provided.