I'm in the same boat, currently looking into childcare in SE23 so I can't advise based on experience. I have been checking ratings on Ofsted - http://www.ofsted.gov.uk/oxcare_providers/list/ it may not be the best info to make a judgement on but I'd feel uncomfortable using any nursery without a 1 or 2 rating. Some mixed feedback on this forum - http://www.mumsnet.com/Talk/nurseries/76...orest-Hill but it's enough for me to have struck Pitta Patta off my list. A list which is pretty small - not all nurseries take in babies.
From this thread I've also looked into NCT - there seems to be a lot of activities in the Forest Hill area for new mums so feeling quiet good about options when the bump becomes a baby.