“Rule: Use the he/him method to decide whether who or whom is correct.

he= who
him= whom

Examples:
Who/whom wrote the letter?
He wrote the letter. Therefore, who is correct.

Who/whom should I vote for?
Should I vote for him? Therefore, whom is correct.” -From, “The Blue Book of Grammar and Punctuation” By: Straus & Kaufman

“Use fewer to describe plural words; use less to describe singular words.

EXAMPLE:
The new product has fewer calories, but less fat.” From, “The Only Grammar Book You’ll Ever Need” By: Susan Thurman