Contact your real estate agent (some even specialize in such transactions) or read up on lease options at the public library. If you have a real estate attorney, ask if he or she has any prepared information you can review. Most bookstores have a fairly hefty real estate book section these days. Many current real estate books have at least a section on lease options.
If you are considering a lease option, be sure you do your homework first. And have an attorney or financial advisor on hand to review any paperwork before you sign.