prenuptial agreement- signed before marriage

My wife was on the verge of getting divorce... It had been amicably solved... Soon the situation may arise near future or later becos i know about her aggressive character and selfishness... We spent the complete expenses of the marriage without a singel penny out of their pocket.. Still she doesn't satisfied.. Basically she is lazy and dont-care kind of girl.... Before she makes another issuess i want to settle everything in paper properly... I mean I am gonna ask their family what we given them so far and likewise we are happy to pen down what they gave to us.... I dont want to get into trouble as well as my family after we spent more on this marriage... They may lie we gave this much and we didn't do anything. Please tell me what is the right procedure to do that ? Is this idea called pre-nup agreement?