The Writers Union of Canada has a page with contract advice on their website. Go to:

Elle Andra-Warner, journalist, photographer and author of best-sellers like Wreck of the Edmund Fitzgerald and The Mounties, offers the following advice about book contracts:

l. License, not assign, your rights, for a specific period, so if you are not happy with the way things are going, you can choose not to renew the license after that time period. If possible, license just rights for your country, so you’ll be free to make your own deal on international rights.

2. Check out the reversion of rights.  What options are there for you to claim reversion of rights: bankruptcy? breach of contract (i.e. unpaid royalties)?  What happens if the publisher sells out to another publisher -- what are your reversion rights?  Have a mechanism somewhere in the contract where you can claim reversion of rights when the publisher/deal goes sour.  A time-specific contract would give you the option to renew or walk away.

3. Get as large an advance as possible.  That way it's in the publisher's interest to promote you/your book to get their advance money back. And, if the company has financial troubles and can't pay future royalties, at least you have the larger advance.

4. Watch the language on the royalty statements.  There should be a date -- annual or semi-annual -- when the royalty statement should be sent to you, along with the royalty payment. The contract should spell out what is to be included in the statement: print run, number of copies sold, stock inventory at end of royalty period, etc. Best royalties are those with royalty percentage calculated on the retail price, not net price.  

5. Watch out for a clause about books sold under 60% off list. If the publisher sells to book clubs or discount stores at under 60% off list - and your contract says that the authors get no royalties on any sales discounted 60% off list -- that means none of these sales count toward the advance royalty that was paid to you.