It is advisable, if you can afford it, to have your manuscript professionally assessed. I admit I am biased (I used to work for them) but without question the number one manuscript assessors in the UK is The Literary Consultancy. They have a team of experienced readers, mostly writers or editors, one of whom, carefully chosen according to your genre, who will go through your manuscript with fine-toothed care and attention and give you detailed feedback.
In Australia I can recommend Sean Doyle at Lynk. (I used to read for him.)
It is essential (in my humble opinion) for all writers, no matter how skilled or experienced, to have their work edited. As time progresses I hope to be able to recommend some editors here, but meanwhile I would like to say a grateful thanks to Shelley Weiner, who did such a wonderful job on my own book (The Worst Country in the World).
Alternatively if you have access to ‘beta readers’ they may be able to give you some useful advice, and/or help with
Proofreading: unless you have access to limitless funds you probably won’t be able to afford an editor and a proofreader (and while some editors don’t mind doing a bit of both it is not strictly speaking their job to pick up on typos). A sharp-eyed friend should be able to help here.
Other recommendations: I welcome recommendations for editors and/or proofreaders from anyone with experience of working with either.
To writer and journalist Michael Burge, who lives on an island off the coast of Queensland, and who gave me such helpful advice on my book.
Michelle Lovi at Odyssey Books – who designed the cover of my book and gave me so much extra information gratis – and others whose websites I have plundered for information such as Freda Lightfoot and Catherine Ryan Howard.