Each hospital has their own set of protocols. We call them "policies and procedures". Though some policies and procedures may vary from hospital to hospital, most will have some similarities.
Policies and procedures are not normally available to the public. You will have to have access to a hospital's intranet to gain access to these documents.
There are quite a few protocols used by Australian hospitals published online - try googling King Edward Memorial Hospital and adding Care of the woman with an epidural in labour, for example.
there are no universal guidelines for midwifery practices on labour wards and I agree with those above that many are still local to the institutions although there is a move towards more universal guidelines that are evidence based (like all guidelines, these need to be flexible to consider individual situations).
As Lynne said above, Cochrane reviews can be useful in highlighting the effect of practices, but this will not necessarily mean that hospitals practice them.
http://www.cochranelibrary.com/
I would also highly recommend the wonderful
Murray, M, Keirse, MJNC, Neilson, J, Crowther, C, Duley, L, Hodnett, E & Hofmeyr, J 2000. A guide to effective care in pregnancy and childbirth (3rd ed.), Oxford University Press, Oxford. Old but very informative, it lists practices as harmful, beneficial or of no effect.
Also, the National Institute for Health and Care excellence (NICE) in the UK has some really robust guidelines which would be followed throughout the UK. https://www.nice.org.uk/
Another issue to consider, is that often the numbers of women in the studies used by even the Cochrane group are very small and so what we base practice on, regarded as 'best evidence', may in fact be questionable and this need critical consideration.
You may be interested in the WHO guidelines on many birth related topics which they are bringing together in a quality f care framework http://www.who.int/maternal_child_adolescent/topics/quality-of-care/en/ and links from this page