These answers are based 31 years of experience, but they remain the views of one man. If you require absolute certainty, the Web is the wrong place to look.
How do you know your model is correct?
What questions should I ask before adding a new compartment or process to a model?
What is a tracer? What is a tracee?
Should we expect or require that every part of a model corresponds to something in the real world?
How do you know that the rate laws for isotopic tracer kinetics are linear?
How can you carry out tracer kinetic experiments in non-steady state systems?
How do you construct nonlinear rate laws?
People often say that with three parameters you can fit an elephant. Isn't that true?
What should I study to prepare for a career in bioinformatics or computational biology?