I was wandering through the website of the SFWA - something I do fairly often although I am not a member of one of the more important writers' organisations in speculative fiction - when I was struck by just what a resource their website is for writers of all genres.
Just to give you a taste the Information Centre has advice for new writers that includes how to present a manuscript, how to sell your work and much more. There's a useful section on contracts and other such areas where it does not pay for a writer to be ignorant. As well there are articles on developing writing skills and what to do once you've finished the novel and the business side kicks in. It also includes Writer Beware which should be required reading for any writer as it exposes the less savoury underbelly of the business.
While it's mainly aimed at speculative fiction writers there's good advice for anyone else too.