I put this here because, English Wonk as I may be, there are bits of the language that give me fits, and the subjunctive case (e.g., "If I were a rich man...") is one of them. I always want to use "was" to make it agree with the singular subject, but subjunctive doesn't work that way.
"Lay/lie" is another one that gets up my nose.
EDIT: More Grammar Girl. Good stuff!
ANOTHER EDIT: I should add that I vehemently disagree with the powers that be regarding the use of "they" as a replacement for "he or she." Call me a heretic if you will, but I say "THEY" and will bite you if you change it to "he" or "she" or "he or she." "They" is elegant and correct.