Definitely read the forums. If you have any specific questions, ask there (do a search first, as many of the beginner questions have already been asked. Check out the articles on hubbing, as well as the help tab at the top.
When writing, write whatever you want to write about. Find topics you enjoy. The more you enjoy what you're writing about, the easier it will be. If you really want to earn money here, do research on top paying keywords, niches, and searches. Bookmark like crazy if you have the time, and just have fun.
Personally, I just write to write and make money while I do something that I enjoy. I do pretty well here, and if you just keep having fun at it, you should as well.
Just remember that HubPages isn't a blogging site, so expect money on articles about how your day went.
In regards to followers, you'll want to write interesting hubs, participate in the forums, and comment on other people's hubs. This will get your name out there and people will want to read your stuff. If they like it, they'll join.
Have fun and participate.