Yes, REDWOOD is a Scrabble word!

Letter values in Scrabble US: R 1, E 1, D 2, W 4, O 1, O 1, D 2.

Is it a valid word?

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

the soft reddish wood of either of two species of sequoia trees
either of two huge coniferous California trees that reach a height of 300 feet; sometimes placed in the Taxodiaceae