I am just starting my final year of a microbiology degree and have decided to follow it with a PhD. When should you begin applying/enquiring? Is it too early now?

You should start to decide what area you would like to research, where you would like to go and what supervisors. Check university websites to check their research areas. Having done this, PhD projects that will be available to you next year will be advertised from around december. By all means enquire to departments about possible placements, but you will notice that projects for a september/october 2006 start will be widely available early next year. Hope this helps, best of luck.

Personally, I'd start looking towards the end of September. I left it until December / January and missed some good opportunities. Plus don't always go by the deadline - get your application in early if you can; I was offered one interview a week before the deadline was up!

Id say once you know the area you want to work in, try to get yourself noticed by supervisors you think you might want to work with asap. Although they may not advertise studentships until later, it will work in your favour if they already recognise your name - shows you are interested enough to approach them. I approached my supervisor in october, although I didnt actually have an interview etc for months afterwards

Start soon. Get an idea of what you want to do and start learning some names and some groups which are big in the field. There's no harm in unsolicited "I've read your work on xyz...are you offering any studentships for 2006/7?" emails. The worst they can say is "no". For Microbiol try Bath, UAE, Warwick, Imperial (medical stuff) or KCL (dental/medical stuff).