I googled zeppelin bombing, and got this, and lots more - don't know if that's enough detail
http://www.spartacus.schoolnet.co.uk/FWWzeppelinraids.htm
Naomi, you could try emailing the Imperial War Museum, or the Museum of London. They should be able to tell you the titles of books which you can then get through inter-library loan, if you don't want to buy them. And the National Sound Archive will have eyewitness accounts, if you can get there.
Also, try Wikipedia - you sometimes have to do a bit of link-following
Emma
<Added>quite thought - is Vera Brittain's Testament of Youth in London during the Zeppelin raids? Can't remember.