Re:Brother in law needs advice.. where else to ask but here!
Hi there Shane. Well the first thing your Brother in law needs is dedication and patience as it takes time to get results when lifting, providing you have a correct program & Diet, many people will stop after a few Weeks or Months if they're not getting results.
Well let me introduce you to (SDB) Squats, Deadlift and Benchpress. These three compound exercises are the most important when lifting & should be his focus as they will increase overall strength and mass. Other exercises should be viewed as supplementary and be built around (SDB). E.G Mon, Bench, Tues, Deadlift & Fri Squats.
Remember form! it's incredibly important when Squatting and Deadlifting that you are following proper form otherwise you will cause yourself a serious injury like a herniated disc, torn knee ligaments etc etc.
Diet. Make sure you are eating two grams of Protein per 1 pound of bodyfat. Obviously Meat & dairy products have the highest amount of protein but you can find a good amount of Protein in Cashew nuts etc.