Yes, WRITINGS is a Scrabble word!

Letter values in Scrabble US: W 4, R 1, I 1, T 1, I 1, N 1, G 2, S 1.

Is it a valid word?

WRITINGS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

the third of three divisions of the Hebrew Scriptures
the act of creating written works
the work of a writer; anything expressed in letters of the alphabet (especially when considered from the point of view of style and effect)
(usually plural) the collected work of an author
letters or symbols that are written or imprinted on a surface to represent the sounds or words of a language
the activity of putting something in written form

produce a literary work
communicate or express by writing
have (one's written work) issued for publication
communicate (with) in writing
communicate by letter
write music
mark or trace on a surface
record data on a computer
write or name the letters that comprise the conventionally accepted form of (a word or part of a word)
create code, write a computer program

Also: written material, piece of writing, committal to writing, drop a line.

Not playable in Scrabble US: HAGIOGRAPHA, KETUBIM.