A couple of things to look out for in the contract:
1. Will you be paid an advance against predicted royalties? If the book fails to meet these predictions will you be expected to return the unearned portion of the advance?
2. Is the royalty calculated on the list price of the book (i.e the price it is for sale at in the shops) or on publisher's net receipts (the price the publisher receives from the bookshop for the book). The latter is more common with trade books but I don't know about academic books. For trade books a royalty of 7.5-10% would be usual in the former and 15-23% on the latter.
3. Is there an 'option' clause? This is a clause that gives the publisher rights over your next book. Many publishing contracts have this but most publishers will delete without much protest if you insist.
4.Who controls subsidiary rights?
5. If the publishers allow the book to go out of print, cam you ask for the rights to revert to you? This is very important, you should be able to request the reversion of rights once the book has been o/p for six months. Related to this is what consitutes o/p. Normally it means when there are 20 copies or less in the publisher's warehouse and no reprint has been ordered.
5. Digital rights have also become really important. If a book is available as an ebook but not in hardcopy is it out of print? Your publisher will most likely not create an ebook out of your book immediately, but what about in 5 years time?
I second the advice given above about not signing immediately. No publisher will mind if you take the contract away with you for consideration.