Tharabg,
According to the two English reference manuals I own, proper punctuation places the comma before the "and" in a series. Journalists often leave out commas before “and” in a series; however, this practice originally started to save space in newspapers. May I suggest that you invest in a writing manual?
I quoted McKernan because two-thirds of the individuals that responded to your inquiry are wrong.
“22.2 (b) To separate items in a series, a comma is used
Sluggo ordered radishes, carrots, garlic, and coffee for breakfast. [series of nouns]
The team swam past the dock, around the lake, and up the creek. [series of prepositional phrases]
The officer asked Eliott where he lived, what he did for a living, why he was out so late, and how he had managed to fall asleep in a tree. [series of noun clauses]
The carrots were old, brown, warm, spotted. [series of adjectives. Occasionally, the and is omitted for rhythm and emphasis or to indicate the series is not exhaustive.” (McKernan 696)
McKernan, John. The Writer's Handbook. 2nd ed. Orlando: Harcourt Brace (1991).
Aaron, Jane E. The Little Brown Compact Handbook. 4th ed. Addison-Wesley (2001): 254-255.