This is by no means an exhaustive list, a lot of links are to Wikipedia articles, but it will hopefully serve as a quick reference list for people who want ideas, maybe for a throwaway reference in a single thread or similar.
List of Roman consuls A list of all the known historical consuls Frome Wikipedia - useful for discovering new/unusual nomina and cognomina
Roman name generator - this site has generators for all sorts of things - check under the 'real names' tab for things like Egyptian and Phoenician names as well as the linked Roman name generator. I believe that the site owner has put in actual historical names from various sources, but don't quote me - as always, when coming up with a name for a new character, run it past the staff to ensure it fits with the board!
Sex and Sexuality:
A Bitter Chain: Reflections on Slavery in Ancient Rome
Interesting discussion about the status of slaves here (homo, non persona est - a man but not a legal individual)
According to Marcel Mauss, in Roman times the persona gradually became "synonymous with the true nature of the individual" but "the slave was excluded from it. servus non habet personam ('a slave has no persona'). He has no personality. He does not own his body; he has no ancestors, no name, no cognomen, no goods of his own."(Source)
servus … homo est, non persona; homo naturae, persona iuris civilis vocabulum
a slave ... is a man (human being), not a person; man (human being) is a word of nature, person (is a word) of civil law.
It means that a slave is a human being, but not a person, in the sense that a "person", legally speaking, is a human being with civil rights and duties (and, of course, a slave cannot have civil rights). (Source)
Map of Roman Britain - includes overlays for villages, villas, vici, roads...
Map of Roman Britain, c 150AD
Roman Britain: Maps from Roman Britain
Kinda for fun but... Tube-style map of Roman roads in Britain