Don't panic if you can't remember when you last changed your oil and filter. These days lubrication-related failures are pretty rare; it'd take some serious neglect to cause any real damage. But here's the point; all of the foregoing unpleasantness can be forestalled by simply performing regular oil changes at the recommended mileages, or more frequently if harsh riding conditions warrant it.
How Often?
What constitutes harsh conditions? Excellent question, grasshopper. Obviously, bikes ridden hard under any conditions should have their oil changed more frequently, as should bikes ridden in extreme temperatures, dusty environments or with heavy loads. For instance, if you're pushing your air-cooled twin up the Rockies, carrying everything including your significant other (who brought along the kitchen sink) in midsummer, an oil change at half the factory-recommended mileage may prove beneficial. Conversely, if your bike is used for lots of short trips, particularly in cold weather, it may not get warm enough to burn off internal condensation. In such cases I'd also recommend halving the factory schedule. Look at it this way, oil is cheap and easy to change--engine parts are neither.
To start with, you'll need a few inexpensive tools. If you don't already own one, find yourself a high-quality wrench, or preferably a socket and breaker bar that fits your oil drain plug, as well as any special tools needed to remove and install the oil filter (your service manual will provide the details). You'll also need something to catch the old oil and contain it until it can be properly disposed of. I'd recommend picking up a combination oil drain pan/storage tank. Typically, these things are available at any auto parts store, cost less than $20 and last a lifetime, plus they hold several motorcycles' worth of drained oil. If that's a bit dear to you—and who isn't budget-minded these days—an old saucepan or cut-down one-gallon plastic container should do the trick. Hell, I've even used a garbage bag in a cardboard box as an impromptu drain bucket. If you opt to use an open drain pan, you'll need some way to store the drained stuff until you can get it to a recycling center, but that's what old soda bottles are for, right?
Where Goes the Goo Go?
Finding a spot to dispose of the waste oil may be problematic. If you aren't sure where to dump it—and no, the nearest storm drain is not an acceptable location—ask the shop where you purchased your oil to recommend a recycling/drop-off location. Most towns have some sort of recycling facility that will accept waste oil, and some shops will accept your old oil if you're a good customer or buy your oil from them. Lastly, if you have any serious aversion toward getting your hands dirty, you may want to pick up a box of latex gloves. And, of course, you will want a bundle of rags handy.
Along with the oil and new filter, I'd recommend picking up a new drain plug gasket and oil filter O-ring (if it's not included with the new filter) just to be on the safe side. Normally I'd segue from that thread directly into a comprehensive (and incredibly boring) debate on OEM-recommend oils and filters versus the incredible variety of oils and filters available through the aftermarket. Sorry to disappoint you, but that's a discussion for a different day.
Believe the Manual
What I will tell you is to follow the manufacturer's oil recommendations as far as weight and blends go. If it tells you 15W50 synthetic oil is what your engine needs, believe the manual. Manufacturers pay some very talented people some very good money to make those determinations. If you second-guess them and dump an energy-conserving 10W30 in there because that's what your buddy uses in his '65 Chevy pickup truck, then you'll have no one to blame but yourself when the clutch starts slipping or the engine goes bang.
Oil filters are a little trickier. Many dealers prefer to sell aftermarket filters as opposed to the OEM version. The profit margins are higher, and in some cases the savings can be passed on to the customer. In my experience—and I must stress this is my opinion—the current crop of aftermarket filters, especially those that carry a reputable brand name, are very good, despite what you may read in some chat rooms. I have no qualms using them in my street motorcycle or racebikes, nor would I hesitate to recommend their use to anyone else. But if you or your local shop prefers the original-equipment filter, then by all means, that's what you should use. Just don't be afraid to visit the aftermarket in this instance.
Out with the Old
In a perfect world we'd always run the engine for a few minutes prior to draining the oil. The reasoning here is twofold. First, warm oil drains more readily than cold oil. But more importantly, when the oil is cold, the sediment it's picked up tends to drop out, collecting in the sump and the rest of the engine's hidden nooks and crannies. When the engine is next started the circulating oil picks the dirt back up and holds it in suspension. By draining the oil when it's at operating temperature the suspended crud flows out along with the oil rather than remaining in the engine. As a side issue, many dry sump engines will leak oil into their crankcases if left sitting for any length of time. Running the engine returns the oil to the tank so it can all be drained without opening the crankcase.
The problem is that in the real world draining hot oil isn't always the most practical solution, especially if you're not used to doing it. For starters, there may be obstacles in your way--smoking-hot exhaust pipes, for instance--that present some formidable challenges. It's hard to concentrate on the task at hand when you're distracted by the smell of barbecuing flesh. Secondly, hot oil tends to drop out of the sump with a rush, and isn't particularly concerned with what it hits. Besides making quite a mess, it will give you a very nasty burn if you're not prepared for it.
Use your best judgment here, especially if you're new to this. While draining the oil hot may be preferable, there's little harm in letting the engine cool off a bit or even draining the oil when the engine's cold, if that makes you feel more comfortable. Be careful here—even though the outer engine case may feel relatively cool, the oil may still be hot enough to scald you. If you do opt to drain the oil with a cold engine, extend the drain period to make certain all the old stuff drains out.
For more articles on how to maintain and modify your motorcycle, see the Tech section of MotorcycleCruiser.com.