I’ve lost count of the number of the people who’ve told me they’re writing a novel. I’ve also met more than my share of successful novelists. Let’s just say that first group of people is a lot larger than the second.
While there are many ways in which a newbie can go wrong, it often boils down to one or more of these common mistakes. 
1 Using stock characters
The tart with a heart of gold. The tall black dude who plays basketball. The gruff schoolmaster. The academic with thick glasses. While stereotypes can occasionally be useful as shorthand, they’re only two-dimensional characters, and that’s not enough to engage readers.
2 Writing real-life dialogue
Yes, you read that right. Realistic dialogue isn’t an echo of real conversation. In everyday life, people use a huge number of filler words and meaningless sounds. Like this.
“Oh, hi, Debbie. Lovely to see you. Yeah, come in, come in. Well, no, I wasn’t really doing anything. Just the ironing, again. It’s OK, no need to take your shoes off. I’m not fussed about the carpet, honest. Right. Now. Um, how about a cup of tea? Or, er, maybe coffee? No, I mean it. I’ve literally just put the kettle on.”
At this rate your reader will be in a coma long before Debbie gets to hear about Mary’s cross-dressing husband.
Realistic dialogue, on the other hand, is a pared-down version of a word-for-word conversation. So it’s more like this.
“Come in, Debbie. Kettle’s just boiled. Look, there’s something I want to talk to you about.”

3 Scenes with overlong description
These usually creep in because the author thinks the writing is so brilliant that it can’t possibly be cut. Sometimes it’s reams of beautiful description or essential back story. If so, find other ways to get the information across. It’s best to drip details elegantly into your story rather than dump them in bucket-loads onto the reader.
4 Stretching the reader’s credulity
Your college student heroine is a virgin, and has no laptop, or indeed any device connected to the internet? In present-day USA? You’d need your reader to be as gullible as your heroine. There are always exceptions, though, as you’ll know if you read Fifty Shades.

5 Using clichés
Maybe your principal character laughs like a drain at her friend’s jokes, goes green with envy at her sister’s new dress, or sweats like a pig at the gym. If so, get rid of hackneyed phrases. Clichés should be avoided like the, er, plague.
6 Ignoring rules of grammar, spelling, or punctuation
Because an editor will fix it all, right? Nope. Your magnum opus may just get binned. Please don’t insult your reader by mixing tenses of verbs, or mistaking it’s for its.
7 Telling instead of showing
‘His pulse pounded and the words he had rehearsed stuck in his dry mouth‘ gives readers a better feel for your character’s predicament than ‘He was scared stiff about the interview.’

8 Shifting points of view
Some books are written from just one character’s perspective, whether it’s in the first person or the third. Others may have two or more. The convention, which I suggest you stick to because it helps the reader no end, is to have just one point of view per scene, or per chapter. Whatever you do, don’t switch a point of view during a scene.
But none of that is a reason to give up if you’ve got a story to tell. The most worthwhile things take effort. Ask a drummer if a drum roll is easy. It is, after the first ten years.
Here’s a selection of books I’ve found useful or inspiring.
Steven King: On Writing. There’s also a blog post from Jon Morrow about it here.
Dorothea Brande: Becoming a Writer
Jessica Bell’s Writing in a Nutshell books, including Writing Workshops to Improve Your Craft, Show and Tell in a Nutshell, and Adverbs and Clichés in a Nutshell.
Roz Morris: Nail Your Novel: why writers abandon books and how you can draft, fix, and finish with confidence.
Good advice or not? Please let me know.
