In terms of finding names of who to pitch to, it's hard if you don't know the genre/business, but a useful thing to do is check the rights deals in the bookseller on a daily, or at least weekly, basis.
It's very useful in terms of finding out who's acquiring and what kind of books are selling.
They are available on their website at
http://www.thebookseller.com/ and there is a panel at the bottom right which lists "latest rights deals". These always include the editor's (and usually agent's) name, and often give a snippet about what they are looking to acquire next.
Obviously it won't give the email address but you can generally track down the formula for each publishing house quite easily - for eg anyone at Harper Collins is first.last@harpercollins.co.uk, anyone at Random House is initialsurname@randomhouse.co.uk, etc etc. Everyone Who's Anyone in UK Publishing is also a good resource.
This might also help you Petal? I can see asking for an email address is tricky, but I don't think there's any harm in asking "who's your editor by the way?" It's not like you're asking them to give you an in, or anything.
I think the bottom line though, is it's bloody tough whichever route you take.