News poster just means you post good news stories in the announcement sections, and with only being here as long as you have, you won't be getting that too soon either.

It means if you login, you have 1 section of the today bar.
For each post you make you gain another section up to a max of 4 posts
After you login at least once and make a minimum of 4 posts, you can't make yourself anymore active for that day, you need to wait for the server to roll over to a new day.

It takes about a month to get 100% activity, yes.