Soldermans Basic Electronics

Capacitors Samples
Ceramic	Mica	Plastic	Plastic
10pf-1uF Leaks a Little. Temperature Sensitive. Unpolarized. Ceramic Dielectric. NPO stable.	Radial. Unpolarized. Mica Dielectric. Costly. Stable. ~100pF	Negligible Leakage. Temperature Tolerant. Unpolarized. Plastic Dielectric. 1nf-10uF. Radial.	Axial. Plastic Dielectric. Unpolarized. 1nf-10uF. 63V-2KV. Inductive.
Capacitors Samples
Trimmer	Trimmer	Tantalum	Surface Mount
Air Dielectric. Very Low Values. Unpolarized. 1-10pf. Variable. Stable.	Plastic Dielectric. Unpolarized. 10-50pF. Crystal Trim. Variable. AF-HF.	1uF -100uF. Low Leakage. Long Shelf Life. Low Power. Polarized. Small Footprint.	Most Types. Small Footprint. Low Power. Low Cost. Multilayer too. Tantalum too.
Capacitors Samples
Tuner Air	Tuner Plastic	Power Electrolytic	Electrolytic
Air Dielectric. Unpolarized. 100-200pf. Antique. Dust Sensitive. Humidity Sensitive.	100-500pf. Plastic. Unpolarized. Tuners. RF-AF. Low Cost.	470uF- 20,000uF. High Ripple Current. High Voltage. More Leakage. Shelf Life Low. Polarized.	1uF-4700uF. Filters. Low Power. Polarized. Electrolytic. Low Shelf Life.

Read More-
Caps Electronics Club, - What Exactly Is A Capacitor,
Capacitance And Capacitors., - Educypedia-Capacitors.

• Voltage Rating is the most important to ensure long operational life and reliability, overrate 1.5 times. If max voltage capacitor will face is 15V then use 25V rating capacitor.
  
• SMPS-ESR means Equivalent series Resistance at high SMPS frequency, the capacitor adds a inductance by the way it is constructed. So use Caps in Parallel for Lower ESR.
  
• For Oscillators and A-D Converters choose Plastic Multilayer Caps as they leak less and have low temperature sensitivity.
  
• Ceramic and Elcap are for Filtering and decoupling and are low priced too.
• Electrolytic Caps back2back in series can make non-polar caps for Low current AC like AF, as used in a cross-over network of loud speaker of stereo system.
  
• NPO "negative-positive-zero" caps and most plastic caps can be used for Oscillators as the negative and positive temperature coefficients are very less.
• Most Plastic Caps are wound, so have inductance, which makes them unsuitable for filtering RF.
• X and Y caps are special EMI-RFI filter caps, suppress interference and are safe at high voltage.