lease option.

i would like to use a lease option strategy to handle the eventual disposal of a new house that will be completed on an investment block i,ve held for a few years.I intend to slant the deal to give hopefully[ a young couple] an excellent opportunity to own their own home.I would like to know the most expedient way to get the legal documents which will serve to warrant/protect both myself and my client in queensland.
i have always found it unwise to consult a lawyer or a engineer without a very precise understanding of what is required.