Two of my sources for the Nora surname are online, but not in English, unfortunately. They are -www.jtosti.com/noms
(in French), andwww.cognomiitaliani.org/cognomi/index.htm
For Code I used Reaney and Wilson's "Dictionary of British Surnames", and "The Oxford Names Companion". You can probably find these in a public library. But there is always www.ancestry.com
, which has information on many surnames from many languages, including their meaning. Also the pages on this site giving the meanings of surnames in various languages.
As far as taking your research further than meaning, you could try www.genforum.com/[name
], replacing [name], of course, with whatever name you are researching. If anyone else is researching that surname they are likely to be posting queries and replies to queries there.