Their are many brands of silver cleaner, and most work well. I like to clean my silver using Never-Dull. You can purchase this at most automotive supply shops or cleaning supplies section in your favorite store. It is very convenient to use. Tear off a piece of wadding, use it, and throw it away.

Silver plate:

Always be very gentle while cleaning silverplate. Never use a polish unless their is visible tarnish that you feel must be removed. You can use a luke warm mild phosphate-free soap solution for everyday type cleaning. Silver plate can be cleaned safely. Just remember, using a cream polish or never-dull,  apply an even amount of light pressure untill tarnish is removed. Than, remove cleaning agent with a soft cloth before it dries on. Some products say to leave on until dried and then buff. I find it less harmfull and abrasive removing before it dries. I like using an old cotton tee shirt for removing cleaner and for a final buffing. Rohs dust cloths works best for buffing your silver. When their are area's that can't be reached, try using a cotton swab to both clean and remove/buff. any good quality silver plate is stamped on the bottom stating the manufacturer name and silver content. example: acme silver co. quadruple s.p on copper.  

Silver:

This is the same procedure as cleaning silver plate except, if needed, don't worry about using a little elbow grease to remove the tarnish. Be sure it is pure silver before doing so.

To minimize the formation of tarnish, keep your silver in an area that is shielded as best as possible from moisture and air. Silver oxidizes from moisture in the air. Try keeping a container of silica in your display case. also, try keeping your display case sealed as best as possible.

I hope this information helps.