Proper drive train maintenance will greatly extend the life of those components. Lubrication is just a part of the process to extend the life of your bicycle. Proper cleaning of the chain and gears is also essential to maintaining your drive train.
Park Tools has a great line up of products designed to make cleaning your bike easy and affordable. The Park CM-5 Chain Scrubber, GSC-1 Gear Clean Brush and CB-2 Citrus Chainbrite and a rag are all you really need to keep your drive train clean.
To get started first take a dry rag and brush any large debris from the chain and gears. Use the Gear Clean Brush to get between the cassette cogs and to help loosen the dirt and grime on your chain.
Next, fill the reservoir of the Chain Scrubber up to the line on the side with Chainbrite and clamp the Scrubber around your chain. Simply hold onto the handle and rotate the crank of your bike so that the chain enters the right end of the Scrubber and exits through the left end. The brushes will scrub the debris from the chain and they will be collected in the reservoir. A strong magnet at the bottom of the reservoir will trap any metal particles that were stuck to your chain. At the left end of the Chain Scrubber is a sponge that will remove the Chainbrite from the chain as it exits the scrubber. This will leave the chain clean and free of debris. You may also choose to wipe the chain down further with a dry rag to make sure all of the degreaser has been removed.
The final step to cleaning your chain is making sure you apply fresh lube. White Lightning Epic Ride wax lubricant or Tri-flow are great options.