I try to use single-word but meaningful names. So I would tend to use "person" rather than "p" but wouldn't go for "newlyAddedPerson".
This goes for query expressions as well - I may well violate this in quick throwaway examples, but I don't generally like:
from p in source
where p.Age > 10
select p.Name;
I'd far rather see
from person in source
where person.Age > 10
select person.Name;