I had a meeting with a UK immigration lawyer yesterday (Barry at Wesley Gryk if anyone needs a recommendation). I'm not sure that everyone needs such advice, since much of what is 'out there' tells you what you need to know.
I have been looking for a ways around the waiting 3 months in Delhi problem that all Brits face. We're lucky to be Australian/British citizens so we plan to apply for an Australian passport in Delhi for baby and apply for baby's British passport from Perth (where Adam's parents live). This would mean we'd be out of Delhi in around 3 weeks instead of 3 months.
Our lawyer sees no pitfalls in this cunning plan but it's a timely reminder to get all paperwork in order long before baby is born, in particular, our surrogate's papers.
For Australians, I came across Meg's brilliant document by document account of the citizenship/passport process: http://www.amaniandbobsurrogacy.blogspot.com/
and click on the photo of the guy on the horse. Thanks Meg!