I am now a member of SFWA. It's kinda surreal.
Joining SFWA has been a goal of mine since I was thirteen. I used to reward myself for meeting my writing goals by reading articles on the SFWA website. I read all of them -- many times. There were a good deal fewer articles then.
I learned that real writers submit stories and collect rejection letters. When I got my first such letter, in all its form-like splendor, I saved it in a folder with pride. I knew I probably wouldn't start selling anything until I had enough of those to wallpaper a room, but I was on my way. Another article covered proper manuscript format. I learned I should write, submit, and then forget about the submission and write something new. Other articles covered bad contracts clauses, vanity presses, and other potential pitfalls.
In short, SFWA established good habits in my malleable young brain and helped me avoid scams. And now I get to join them. Just in time to vote for the Nebula Awards.