Thinking about the response to my royalty tweet, and @nikeshshukla's research that the mysteries of the publishing process are creating barriers, here is a very general guide to the trad pub model from an author's perspective. Contracts vary, these are broad strokes, stay calm...

If you have been taken on by an agent (some writers rep themselves, I would recommend representation every time), once you are both happy with your manuscript (MS), your agent will put it out 'on submission'. This means they will send it out to publishers and hope someone bites.

At this point, several things could happen:
1) No-one wants to buy it. Could be timing, could be market, could be bad luck... who knows. If lots of publishers are saying the same (correctable) thing, you might tweak your MS and try again. Or this one isn't going to fly. Yuck.

2) One publisher loves it SO much they offer a pre-empt. This means they are prepared to pay an advance that they think will take it off the table for other publishers. Now it's a gamble - do you take the money that's being offered, or do you hold out for more?

3) Lots of publishers love your MS, so your agent runs an auction. Publishers bid, you choose the best offer. Might be highest advance or best overall deal that wins the day for you - or maybe there's a publisher you really want to work with. You decide with your agent.

4) One publisher likes your MS, they offer (knowing they are the sole bidder) and you accept or decline it.

Whichever happy event, you've GOT A BOOK DEAL! Huzzah - now it's on to contracts.

This is one of the reasons I would always recommend an agent, or insist that you have someone knowledgeable helping you at this stage. Publishing contracts are as transparent as the Enigma code. They are full of clauses that need an expert eye to protect your interests.

The main negotiating points are likely to be:
a) Size and nature of advance
b) Share of royalty
c) World rights (who has them)
d) Other ancillary rights - ie TV/Film

Now at this point, I can really only speak with any authority about my experiences - all of these things vary MASSIVELY according to your agent, publisher, sales history, sway in the market - and they are shrouded in mystery for many reasons.

But I think the most important thing is what an 'advance' actually means. A lot of people think this is a sale price for your MS - not so. It is a loan/investment against your future sales - before you see any royalties, you need to pay it back with your share from sales.

Advances vary wildly, from £100s to £millions. Broadly, advances in adult publishing are higher than children's, commercial publishing higher than trade. But a huge variation depending on who you and your publisher are.

But always remember - and this cannot be stressed enough - that before you see ANY more money from your book sales, you have to pay this money back. Your publisher is bearing all the cost/risk of publishing your book at this point, so they need to recoup from sales.

Your agent will negotiate your advance, but it's also super important to get a good deal on royalties - this is where your long-term income will come from. To paraphrase, advance is vanity, royalty is sanity. This is your share of your work. Fight hard for it.

Royalties are total pieces of string, but I think it's fair to say that most fall between 6% - 10%. If you have an illustrated book or a co-writer, you will split the royalties with your co-creator. Your royalty share might rise with sales - this is again is where you need help.

Your publisher might acquire world rights (I believe this is quite standard in kids' publishing), or you might keep them, but either way, every time you sell your book to a country, that advance goes against yours, getting you closer to 'earn out' - ie, your advance is paid back.

Many publishers want to and will acquire other rights (TV/Film, games, merchandise etc). These are to be carefully negotiated and considered. They can potentially be huge - more so than a book! Don't sign them away lightly - publishing is littered with salutary tales of this.

Another thing to be very wary of are so-called 'special sales', where publishers sell high discount for high bulk - this is how books can be sold for pennies. In these cases your share will be minute - the @Soc_of_Authors is campaigning hard for greater transparency on these.

Your royalty share of ebooks is likely to be higher (maybe 20 - 30%) and audiobooks around the same - although sales of both in kids' books is relatively modest for most.

I'm sure there's a great deal I haven't covered here, but I hope that it gives an idea of some of the bigger points. What I would urge anyone selling their creativity to do is to inform themselves - don't go into any negotiation blind. Publishers are lovely people (mostly!), but

they are running a business, not doing you a favour. Remember that. They hope they will make money with, for and from you, so be savvy. Get professional advice, arm yourself with knowledge and don't be afraid to ask those of us who are happy to help you. GOOD LUCK!!! xxx

Ps - one thing I forgot! Advances are rarely paid in one lump, the standard is three parts: a third on signature of contracts, a third on delivery of your MS ('delivery' is vague, but not usually first draft IME, a few drafts along the process) and a third on publication.

These points can be YEARS apart, so remember that before you pack in your job and put a deposit down on a yacht (as if).