Being a new writer I was astounded by the help and advice that established writers gave freely. I would thank them all but it would fill this page. However, special thanks go to Peter F Hamilton, Alastair Reynolds, Iain Banks, Roger Ellory and Rog Peyton of the BSFG.
With that in mind, here is my advice for new or aspiring writers.
At one of the BSFG meetings I spoke to Charlie Stross about writing and he told me that there was only one book that he could recommend that I read on getting published: Stephen Kings "On Writing, a memoir of the craft". Which is part biographical and part on how to write great books. I thoroughly agree with Charlie Stross on this, get Stephen King's book and read it!
Roger Ellory is well known for excellent crime fiction and his advice is second to none. He emailed me his guide on how to get published, in short, perseverance and a pinch of luck. When I asked him about writing groups, his advice was considered and thoughtful. Writing groups can be very good, but you need to find one that is critical of your work, not a bunch of people saying how great your writing is. He also suggested that to be cautious of the advice as most writing groups people suggest alternatives and these alternatives are how they would write the story, not necessarily how to "fix" your story or improve it. I have joined an online writing group through the BSFA. I can only recommend joining one of these to improve your writing.
I would also like to recommend Dan Simmons Writing Well on his website. Dan Simmons taught creative writing for eighteen years at elementary school, and at various college and writing courses, so he might know a thing or two about writing. He has also written a good number of ber luddy good books to boot. Here is free advice from one of the masters! I would set aside a day or two to read all of these.
It has also been said that you are not a writer until you have written a million words, I happen to disagree with that. In my opinion, just writing for the sake of writing wont improve your craft unless you have a serious desire to get better at it.
And finally, the advice that Peter F Hamilton gave me was "Practice, practice and more practice".