Rule #1: Avoid the wet cloth you speak of!
Water is destructive to just about anything over a period of time. You may even already notice water rings on the very same furniture you are asking about already. Do Not Use Water to clean furniture. In most cases, your store bought furniture cleaner will work.
Rule #2: Avoid the abrasive cloths.
Clothes with a very low thread count that you can basically see through can scratch your furniture. Instead, use a soft cloth that doesn't leave traces of itself behind. A good microfiber cloth is good, but only if it doesn't leave deposits of itself.
Rule #3: Avoid human nature
This may be easy for some and tough for others. Don't place cups (especially cold ones) directly on the furniture itself - you are setting yourself up for those dreaded water rings
Instead, use coasters
Shine and protect!
If you're wanting to stay clear of the store-bought cleaners, you could use a blend of olive oil and lemon (try to shoot for a
4:3 mix). This will not only keep your furniture nice and shiny, but lemon itself is a natural preservative and will also leave behind a nice, fresh fragrance! Just place in an empty spray bottle and you're done!