At Etsy we have an amazing research and strategy team, and they helped immensely in getting the information architecture right. They performed card sorts with research partcipants to understand what were the most logical buckets for all the types of information the help center included, and we ended up with these top categories
My next step was to spend time with my co-workers on the support team, my product manager, and key engineers, to come up with wireframes to iron out any kinks, and come up with answers to problems that might arise. In general, we knew if users were coming to the help center, they were probably frustrated that something wasn't going right. We knew we needed to make these pages as focused and to the point as possible.
I then moved on to visual design, making sure everything we had come up with in the wireframe stage made the most sense. Our team also created a tappable prototype and brought in a handful of research participants to perform usability studies, making sure we were on the right track before we started officially launching the new help center.
We also created all the pages on mobile at the same time. One of the key pages that we focused on was the contact page and making that as seamless for users as possible.