I've just started a PhD on the 1st of Sept in Biotechnology. How much work/understanding should I have done two weeks in? by the middle of November and by Christmas? I really dont have a clue what im suposed to know or have done. Any advice would be great.

In your first three months you'll be spending your time finding your feet. Don't expect to understand everything straight away. You should be learning techniques and beginning to pick up a background knowledge of the work surrounding your project.

I was in the same position - nobody ever told me what was expected. If your supervisor is happy then you can relax. Try and get some new results by christmas (just one or two)- takes a lot of pressure off.