The industry tends to dictate what rates an agent can charge, so for a good agent, the fees are transparent. Usually it's a percentage of any money the writer earns plus many deduct some minor administration fees (copying, long-distance calls etc.) ? but again, the good ones agree these up front and itemize them when they deduct.

Agents, on the whole, work on commission. They don't earn a penny until the writer does ? although they tend to earn it slightly quicker as they get the royalty cheque and deduct their fee before turning the lion's share over to the author.

This means that if they can't sell your story, they don't get paid. This is arguably the main reason agents are so selective. They won't just post out any old manuscript in the hope of gaining a sale.

Instead they will work with the author, maximizing the manuscript by giving honest advice on any improvements. They'll not only send out your manuscript, but they'll pitch it to the editors and follow up to see if there's interest.

They'll ensure the writer gets the best deal possible (which in turn maximizes their percentage of course) but which writer will argue at that?

And finally, they'll act as mentor and supporter, advising the writer on trends in the industry etc.

The bad agents are typically the ones that can't sell the manuscript. So they have to find other ways of making money.

Before I list some of the poor practices that exist, the best bit of advice I've ever heard about agents is this:

Money flows in the direction of the author

Money should never, ever travel the other way. If it does, there is no incentive for the agent to make the effort to actually sell the book. There are always willing authors who are so delighted that an agent is interested in them, that they'll happily part with a little bit of hard-earned cash to realise their ultimate dream.

So how do you spot a bad one? Although many genuine agents use some of the practices below, any multiple would make me more than suspicious.

1. They ask for reading fees.

2. They ask for cash up front with a weak reason for doing so, perhaps a processing fee.

3. They can't/won't let you know who else they represent. Reputable agents are proud of their clientele and can't wait to tell you whom they represent. Bad agents don't sell and so have no names to give you.

4. They don't come from a literary background. The majority of agents used to work in publishing, or at least somewhere in the book world. They know the industry and they have good contacts.

5. New agencies aren't necessarily bad ones, but they should be treated with caution ? especially if they ask for money.

6. They ask for administration costs up front. A good agent will believe in you and deduct any fees from your first royalty cheque.

7. They ask for a fee to recommend changes to make your manuscript more saleable. A good agent will realise that making your story better is in their interest and offer the advice for free ? as long as you sign with them.

8. They refer you to a manuscript doctoring company (and typically receive a percentage of the fee for doing so).

Having said all of this, good agents are in the majority ? it's just the bad ones are easier to convince to represent you. Most writers are so excited that an agent is interested, they forget the part about it being a partnership and being selective in whom they associate with.

A good agent becomes your best friend and is worth convincing to begin that relationship. Stick to the reputable names and it'll work out all right in the end.