Diesel Bombers - New Guy From Northern NJ

Hello all. I'm Steve from northern NJ (Morris County). My truck is a 2004 Ram 3500 SLT 4x4 diesel. She is very special to me because she used to be my Dad's. My Dad was a hot-rodder in his day. He had a 68 Roadrunner that he used to street drag for $$$, a 70 Challenger 440 w/6 pack, and 2 Mr Norm's Demons. He got sick in October 2009, was in and out of the hospital for a few months until he was finally diagnosed w/multiple myeloma. He started chemo and things looked promising but he took a turn for the worse and past on March 1st, 2010 at 3PM. So as you can imagine his truck has sentimental value to me. I am planning to restore/modify/upgrade it but don't want to destroy it. I have been a car guy my entire life but am not as familiar with diesel trucks. I had a 97 Ford F-250 4x4 diesel, but didnt do too much too it outside of an exhaust, intake, and Pre-Luber.
My intentions here are to pick your collective brains for advise (lol) in order to establish a game plan on what to do to the truck and whose parts to use. And if i can help any of you, give some of my own advise. Thanks for listening. -Steve