There are two types of chains, o-ring & non o-ring.  O-ring chains have, you guessed it, a small o-ring built in to them and the non o-ring does not. The o-rings are used to keep grease & lube inside your chain, keeping the mud & dirt out.

A well maintained o-ring (or X-ring) chain provides less drag, requires less maintenance, & lasts a lot longer. An o-ring chain requires attention just like everything else on your bike. Sand & mud are not the best for o-ring chains.

You should lube your chain every 500 miles. Wax based chain lube eliminates "fling off" & seals the lube to the chain. It provides excellent rust protection for both o-ring and conventional chains.

Non wax chain lube will have to be applied more often and with non wax it will be easier to clean your chain. There are positives and negatives to both wax and non wax.

Tip:  Lube your chain after you ride, when the chain is warm.  The heat will cause the lube to be drawn into the chain as it cools. Lube your chain with the motor off and the bike in neutral.

It's a good idea to clean your chain every 3000 miles or whenever you change your oil.

There are many great cleaners on the market. You can even get a chain cleaning kit. Motorex has a kit that includes Chain clean, a cleaning cloth, and chain lube. It retails around $30.  You can take it one step further and get "The Grunge Brush".  It's o-ring safe and will also clean sprockets, brakes, & other components. Retails around $15.

Chain Adjustment: Your owners manual will have exact requirements for your bike, but the rule of thumb is about 1-1.5 inches of slack. Slack is how much the chain will move up and down freely at a point halfway between the two sprockets.  If your chain needs adjustment, your owner's manual will have the information you need to tighten/loosen it as there are many types of adjustment.