I don't want to ruin your enthusiasm but I think the best tool, and mostly recognized, is experience in the field. IT-security often touches a wide range of items, which is hard to capture in a single training. Which is also why f.e. the CISSP certification requires a number of years working experience.
You could look at more specific certifications and trainings that focus on a single topic.
OSCP might be something as well, as I think anyone that completes their 24 hour exam has proven a certain capacity for the job but even then, pentesting also requires a wide range of knowledge.
My recommendation for you is try and get a job as a helpdesk specialist and work your way up from there. In my experience, the best security professional is the one with the full breadth of knowledge regarding operating systems, hardware/software, databases, networking, vulnerabilities, etc., and all the little intricacies that make them function-things you don't really learn by reading books. As opposed to 10 years ago, today's brand of helpdesk specialists get a wide range of experiences, instead of just being focused one or 2 tasks. I don't know what your age is and how much you are looking to fast-track this process but if you want to do this the right way I would recommend following my process. The last thing you would want to do is to read a book, study weeks for a test, pass the test and get a job, then suck at the job and fail.
Hope this helps
@dharvey32 Great advice! Helpdesk experience also teaches you about customer service. Also gain as much experience as you can. Even if you have to do it yourself. I set up a lab environment and practiced all kinds of setup and hacking to gain the experience I couldn't gain at work.