In this month's Authors Guild Bulletin, Mark L. Levine warns writers to be very wary of publishers offering a so-called "term of license" contract (signing you for seven to ten years with an option to renew) unless you are already a best-selling author or are negotiating paperback or reprint rights to an existing work.
If they're offering it to you as a novice writer, then it's a big warning sign that "the publisher in not a bona fide trade or academic publisher or even a bona fide print-on-demand one but a vanity publisher masquerading as a bona fide POD publisher." He offers some more good advice:
[…]They typically will not publish any copies other than those ordered at the authors discount. Apparently, the total number of books purchases for friends and relativesat the "special" author's price by the presumably large number of people taken in by this scheme makes it a profitable venture for the ethically challenge.
[…]If you are still interested in proceeding in the hope that your publisher is bona fide, be sure to insert, in addition to the requirement that the book be published within a specified time period at the publisher's sole expense, language stating tha the number of print-on-demand copies of the book initially published at the publisher's expense "will not be less than ______ copies" (eg 500 or 1000). Language like this, as well as a good out-of-print clause, should flush out the intentions of the publisher and save you from a bad surprise.