There are a variety of different kits made specifically for sensor cleaning, available at most good camera stores.
Some warnings, though: do not try to blow with your mouth - any spittle, even microscopic, particles will be disastrous! Do not use canned air - WAY too strong and will likely cause damage. Do not use anything that comes in contact with the sensor other than a special brush or swab that is made specifically and certified for CCD or CMOS cleaning. As well, note that some of the major camera manufacturers do not recommend anthing other than using the sensor cleaning (vibration) function or sending it in for bench repair, the latter of which is more costly than purchasing a kit.
A bulb air blower (or the kind with an ultra-soft brush) usually does the trick and there are some new and reportedly effective cleaning kits around, such as the one by Delkin Devices or one from a Canadian company by the name of VisibleDust. In all openness, I have not tried the kits from these two manufacturers, but have heard they are good. I have tried a basic bulb air blower and it has done the trick.
A caveat: I would not recommend anything other than what the manufacturer endorses, so you're on your own for whatever decision you make; just know that damaging a CCD or CMOS is very easy to do! Also, if you decide to use a kit or blower bulb, you'll need to use the "mirror up" or "bulb" function on the cam in order to get to the CCD.