For many, the choice to buy a cooperative apartment or a condominium is often perfect in terms of availability, location and finances. It is one of the most important decisions that families and individuals will ever make in their lifetimes, and should not therefore be made without thoroughly investigating the property that is being considered.
The office of the Attorney General of New York has published an excellent brochure that may serve to assist prospective purchasers.
ARC joins the Attorney General in strongly suggesting that the guidelines presented be at least perused, if not carefully followed, before venturing into the purchase of a home (of any sort).
The brochure is available for download here: Before You Buy A Co-op
Another source that may be of value to you is published by Habitat magazine.