I'll "yes and" Gregg's answer and say that this will really vary by company size and complexity. I was at a startup where my 30-day goals included creating buyer personas and enabling the sales team to talk to the decision-makers. So it was more like a 10-20-30 day goals as described below.
At SAP, the organization is so sprawling and complex that the my goals were actually 60-120-180. I've been with the company for almost a year and I'm still getting introduced to some of the far-flung enablement teams spread across the globe.
The key is to set some measurable goals against appropriate milestones.
Every time I join a new organization, I ask for the same things:
From there I construct a 30-60-90 day plan to meet people, learn the products, and craft a strategy for the products that will lead to measurable success.
This is a really great question and one that will define the role you play in the organization greatly. I like to say that when the PMM team sits in Product Management, they become capital P Product, lowercase m marketing managers (PmM). The focus is heavy on technical capabilities and you're going to spend a less time with the Marketing team. Often this felt like I was throwing my work "over the wall" to the marketing team.
When I've sat in Marketing it's reversed. Lowercase p, capital M (pMM) and the role is much more focused on marketing activities with less time spent on technical expertise. In these scenarios, I had to be focused on immersing myself in the PM team, and making sure I understood what they were building and why. It's tempting to get sucked into all the marketing programs, but that decreases the value you provide to those teams. You know you're not driving value to Marketing if they are going to the PMs to get the answers to their questions. You need to be the first stop for their questions.
I've done both and had a modicum of success in both. My preferred scenario is to be managed in Marketing, but have my seat as close to the Product team as possible. In one role that meant that I was two floors away from the rest of the Marketing team because I sat with the PMs. It meant that I was up and down the stairs a dozen times a day, but I also got to immerse myself in the daily work of the PM team.
This is an interesting question. In my experience, the most important soft skills needed for PMMs are influence management, and public speaking skills.
Influence management would be getting people from outside of your department or team to work on your project. Good influence management is not just asking people to help, but making sure they understand the value of the work they're doing. If someone says they can't help, going to their manager to help with priorities needs to be done with a soft touch. Being a tyrant to get your projects done won't get you far in the long term.
Public speaking comes into play with enablement and training sessions, as well as just speaking extemporaneously about your solution, your goals, and what you're trying to accomplish. For any products I work on, I build a baseline presentation and craft the story to tell people "who, what, when, where, why, how" in an efficient manner.
Hard skills will vary from company to company, but I've always found that an ability to crunch data is highly valued by senior leaders. Taking a complex raw data set (raw research, sales data, etc.) and turning it into insights that inform your decisions is very compelling.
In smaller organizations, I've found this is much harder. The marketing team, sales team, and product team might all sit very close to each other. Small organizations essentially require everyone to have a technical/product expertise that just doesn't happen in larger orgs. The sales teams will just ask the PM directly, and the marketing teams will focus on the key messaging for the product(s) that drive the company.
As the company grows, the roles required within marketing, sales, and product get more specialized and the spaces between them grow. There might be multiple products, geographies, or lines of business. This is where Product Marketing Managers really get to shine. Taking the technical solution built by product, and creating a sales message that can be amplified by marketing in properly targeted campaigns is critical.
Thus if you're in a small company as a Product Marketing Manager, you need to make sure that you're driving that value for all three teams I mentioned above. Defining the product messaging for the PM, aligning a marketing campaign to deliver a robust pipeline of leads, and enabling sales with the right pitch and materials to close deals.
If the marketing machine has been created correctly, this should be fairly measureable. In a prior role we had an excellent demand generation team who tracked how different messaging worked over time. We could run little A/B tests on our dotcom and outreach to see if any messages were particularly effective.
All of this is really nibbling around the edges though. Your product messaging needs to clearly articulate the problem customers face, and how the product helps them.
A colleague once said that his rule of thumb is that the solution needs to drive 10X the value to a customer over status quo in order to close the deal. So if you're selling a $1,000 you need to be able to demonstrate 10X in cost savings, revenue growth (or whatever value creation you deliver) to a customer.