It really depends on your level of experience in sustainability and what you are looking to get out of these resources, there are differences between the masterclass suites and the auditor certification course. 

The Sustainability Consulting Masterclass is a great place to start if you want to figure out the basics and if you want to learn more about the business-oriented aspects of sustainability consulting.  Sustainability 101, within the Sustainability Consulting Masterclass series, addresses topics such as the four main categories of sustainability consultancies, positioning your past experience to break into this competitive field, and resources to stay up-to-date with emerging sustainability issues.  The rest of the series covers topics such as high-growth areas within sustainability consulting, clients you can expect to see hiring, writing proposals and contracts for sustainability consulting engagements, project management tools, communication strategies, and even suggestions for how to approach pricing.

The Green Auditors Certification is great for those that are ready to get started with a tangible green audit and is very action oriented.  If you have a good foundation of sustainability, the auditor certification might be easier to jump right in to.  You receive a host of tactical tools (surveys, spreadsheets, calculators, report templates) to make green audits a simple, consistent process, including a copy of Sustainability 101: A Toolkit for Your Business.  You'll also have access to SSC’s collection of green recommendations and results (for example, show your clients how their carbon footprint compares to other similar organizations).

The next step would be to take the Chief Sustainability Officer (CSO) Masterclass Series, which is a great way to take the elements from audit findings and mold them into a strategic long-term plan.  The CSO masterclass is designed to help people develop strategic sustainability plans whether you are an in-house resource or a consultant.  You’ll be actively involved from the start—putting ideas into context, applying them to your own organization, and sharing information with your peers. At the end of this series, you’ll walk away with not just a solid understanding of what it takes to be a Chief Sustainability Officer, but also a tangible plan for integrating sustainability into your organization. 

It's best to view all of these training opportunities as pieces that work together, building your skill set along the way.