I'm a new Hubber and I've already learned a few good lessons so I thought I'd share:
1. Yes, spend time learning about HubPages. That includes spending time in the Learning Center, as well as, spending time reading other Hubs and Hub profiles. Getting to understand how Hubs operates AND how other writers are navigating the site is very helpful.
2. When you first being writing, I would agree that you should right about topics you know WELL. By writing what you know you will be able to complete several Hubs and learn from that experience. I discovered that my curiosities to learn more about a subject slowed me down and in some ways frustrated me.
3. Like any community, it is best to participate and participate consistently. You begin to meet people who are quite willing to help and guide you in your pursuits. It's also nice to not feel completely alone while you are working on what tends to be a solitary craft.
4. Keep your focus. Decide what it is you wish to accomplish and make a plan to achieve it. Because there is so much to learn, if your efforts are not disciplined you may not reach your goals. Sure, I'd like to build a residual income with HubPages, but my primary goals right now are to learn how to write great articles and get them found.
5. Commit. Join a Hub Challenge. Write your thoughts down. Do it.