You won’t be able to find good information about writers online; it’s one place where you still have to rely on old-fashioned print materials.
An overlooked resource on the ground floor of the State Library are the 445 (and counting) volumes of the Contemporary Authors series. This series provides biographies for authors, lists of books they’ve written, summaries of reviews of their work, and contact addresses.
I was amazed to find a lengthy article on the forgotten science fiction writer, John Christopher (real name Sam Youd), including his home address. I’ve been wanting to write him a fan letter for years, and now I know where to send it. (He’s 85, and so I hope he is still alive.) I also found an article on the little-known New Zealand writer, Ian Cross; it had a few paragraphs of biography on him and reviews of all of his works. I was amazed; previously, I’d found nothing on him!
You need to start by checking the cumulative index to see where the original entry for the author is, and where any updates can be found. The full title of the series is:
Contemporary authors : a bio-bibliographical guide to current authors and their works / [edited by] James M. Ethridge [and others].
It’s call number is QB/800, but that doesn’t mean much, because they are shelves separately in the eastern corner of the ground floor.