Hi @hubspot,
Great question! I recommend your marketing interns start with the Inbound Certification and (especially!) Inbound Marketing Certification. These will provide the most context on the state of inbound marketing. The latter will also start to touch on the implementing inbound strategies.
Depending on the interns’ exact roles, we do also have certifications that cover Content Marketing, Email Marketing, and Social Media Marketing that could help with more specific strategy/application needs.
Tracks are a little less time intensive and targeted (in terms of subject matter). We have a business writing track with author Daniel Pink (see here) that may be useful. The Building Sustainable Traffic for Business Growth track, taught by Matt Howell-Barby, also breaks SEO down in an incredibly accessible way.
Any and all content can also be taken as bite sized lesson (usually 30 minutes or less). So if time is a worry, I recommend having your interns look at the Lesson tab first to make sure they are getting the information they need — fast.
Best,
Jorie