I just got a 2002 7.3L Crew Cab! :D

[ticopowell]

So I decided to upgrade my truck... to a powerstroke , It is the 7.3, Crew Cab, 6ish foot bed, and it has a manual tranny, and now that I have my very first diesel truck I have a few questions.
First: When I do upgrade my truck to get better performance, what should I do first?
Second: I need to improve my vocabulary/truck knowledge... so I have read a lot of terms on diesels, such as HPOP, and while I know that an HPOP is a High Pressure Oil Pump, I don't exactly know what that means or what it does or why it helps. Another is the difference in fuel injectors, stage one, two, three, hybrid, or whatever else there is, where can I read to learn why these are different, and which I would want?
Third: What do I need to worry about for my truck's future health? is it fairly straight forward? just keep the fluids changed when needed and dont hit anything or is there more that I now need to worry about?
Thanks in advance for all the help and answers!