Get Writing is produced by BBC Learning which aims to help people get back into or start out in creative writing. It’s not aimed at those who want to be professional writers, but should certainly help you improve your chances of getting published.At the heart of the site is the Read and Review section where site users critique each other's work. There's also lots of articles and advice.
Worth checking out the copyright section before submitting anything to the site, however. By agreeing to the terms and conditions of the site you grant the BBC "a perpetual, non-exclusive licence" to your work.
It's not entirely clear how Get Writing fits in with the BBC Writers' Room, that carries a lot of similar information but is aimed more at people wanting to submit scripts for TV or radio.