I installed code on this blog that allows Google Analytics to monitor usage. This can show which browsers and Operating Systems are viewing the site, and in some cases it will also show the Network you're on when you view the site, but not who you are or where you are — other than possibly identifying the country, and perhaps the city, you are in.
If you sign-up for email updates, I use FeedBlitz to provide this. If you subscribe to FeedBlitz, I can view the email address you provide. I won't provide that email address to anyone else without your permission.
If you subscribe to email updates, you must verify your email address to prevent spam. The Spam Act 2003 (Cth) requires that you musn't receive commercial electronic messages unless you consent to it, the sender provides identifying information in email, and you can unsubscribe. I reckon the emails you get from this blog aren't commercial, but in any event, the FeedBlitz service meets those three requirements.
The Privacy Act 1988 (Cth) applies to any personal information you provide to me, and so the National Privacy Principles apply to protect that information. See the Privacy Commissioner's Information Sheet 12-2001 Coverage of and Exemptions from the Private Sector Provisions for more information about how and why the National Privacy Principles apply. In practice, the only personal information I'm likely to get from you is your email address. I won't collect any other information about you, but information about your online activity might be collected by third parties.