To steal a line from late comedian Rodney Dangerfield, passive components "just can't get no respect". Yet despite their undeserved lowly status in the component hierarchy, they are still very vital and essential in all electronic circuits and systems, and especially so for power-related designs. I've seen many circuits with 10-to-20 passives per IC, when you look at the schematic or bill of materials (BOM), and that's something that can't be ignored.
It's not just choosing the right nominal value and key parameters for that resistor, capacitor, or inductor (the three leading categories of passives) that is critical; you also have to worry about secondary specifications, construction details, and other subtleties. A carbon-composition, 50 Ω, ½ W resistor is not the same as a thin-film device with the same apparent, top-level specifcations; there are issues of temperature coefficient (tempco), surge withstand, size, and other less-obvious but still vital factors.
In order to give some "air time" to passives (to use an old, quaint phrase) we've looked over our many design articles published here and at sibling sites in the past few years and picked some that have rated highly among readers, as measured by page views and their "long tail"–one undeniable aspect of passives as a category is that so much of the information about them is valid and valuable for a relatively long time, compared to active components.
Some of these articles focus on the passive component itself, while others are about getting the most when using the particular component in a design. Here are the ones you found worth your time (they not shown in any sort of rank order, BTW):
We hope you still find them useful, whether you are revisiting them or seeing them for the first time.♦