Learncoach is New Zealand based and provides useful video tutorials. Below are the links to the Youtube playlists.
No Brain Too Small is a New Zealand revision site for Science. There are last minute revision sheets, flash cards, past exam questions and other good activities found on the site.
Doing past NCEA exam papers is a really good way to study, here are the links to past exams/solutions.
Past exam papers 91170, 91171, 91173
Answers (Look for Assessment Schedules)
Cut Scores
Past exam papers 91170, 91171, 91173
Answers (Look for Assessment Schedules)
Cut Scores