Whether you parked your Steed for the Winter, or Rode throughout, this is the time to clean it up, and address any Service Issues. Doing this Service yourself can save a great deal of Money (better spent on Fuel!), in addition to becoming familiar with your Machine. Understanding how your Bike works, and what you need to do to repair it is vital in forseeing issues as they begin to appear, prior to them leaving you stranded on the road!
One of the most overlooked items is the Drive Chain, and although it is a bit of a chore, it is a very important item to address. Cleaning your Drive Chain is not very difficult to do, although it does require you to remove it from the Bike, which, if you include remounting it, is really the bulk of the work! A regularly cleaned Drive Chain will last longer, and it should be done at least once a year, to clean off excess Chain Oil Build Up, Flush Grit from the Rollers, and fully Renew the Chain Oil.
This a layout of how to get it done:

Step 1: Remove the Drive Chain. Depending on the Bike, and the Type of Chain, it may involve some serious dismantling if there is no Master Link. Consult a Workshop Manual for your Machine if you are not familiar with the procedure.

Step 2: Lay the Drive Chain in a suitable Pan. A Cookie Sheet is used in the Pictures Below. Never soak the Drive Chain in any type of Solution! The majority of Modern Drive Chains are O-ring Chains, and cleaning them in harsh Solvents will damage the Rubber O-rings that are pinched between the Links, which serve to keep Oil in, and Water/Grit out, extending the Life of the Chain. Non O-ring Chains look more like a Bicycle Chain, and you can identify if your Chain is an O-ring by looking between the Outside/Inside Links where you will find the small Rubber O-rings. O-ring Drive Chains should always be washed in either Diesel, or Kerosene, as these do not cause any damage to the Rubber, and effectively remove old Oils. I prefer Diesel, as it smells better than Kerosene!
Pour a small amount over the Drive Chain, and allow it to set for a moment, before scrubbing it with a Stiff Bristle Brush. Pictured are Nylon Bristles, which are strong enough to remove grime, but do not damage the O-rings. Never use a Wire Brush to clean an O-ring Drive Chain! To minimumize waste, wash both sides of the Chain with the same Solution, by dabbing the Brush into the material still in the Pan. By keeping it coiled, it can be easily flipped over for the other side. Make sure to work between the Links.

Step 3: Using Compressed Air, and a Nail with which to hang the Drive Chain from (in a place that won't mater if it gets grimy), blast the Drive Chain free of the Solution, and any remaining grime that is loose on it. Work from top to bottom down each side, stopping with a rag to wipe it down a few times. This Step may take several passes before the Drive Chain is clean, and free of Solution. Take some time during this Step to inspect each of the Rollers, to make certain that they spin freely. If you find a Roller(s) that does not, return to the Pan, and work it gently with a pair of Needle Nose Plyers, and a liberal amount of Solution untill it breaks free. A stuck Roller will cause a Drive Chain to bind at that Link, which will fail if neglected, resulting in a pile of Chain wadded up in the Sprocket Box, likely destroying the Countershaft Sprocket!