In life, there are high- and low-maintenance people. The high-maintenance ones usually need constant attention and reinforcement that they're performing well, while the low ones don't give you any trouble--until the day they go postal. The same can be said about many components in your truck. For example, there's the engine, which requires continual vigilance of oil and fuel. However, things don't get much more trouble-free than your vehicle's plumbing--until the day something bursts.
Whether you're in need of new hoses and accompanying components, want to swap in some hardware that will be more sturdy for your application, or simply yearn to dress up your ride, you need to have a basic understanding of what's out there and what will work where in your 4x4.