You have a few options. I use a small paint brush for the body, if it's dusty, and a soft brush followed by a Lens Pen and/or microfibre cloth with cleaning fluid for the lenses. There's no need to overdo this.
You don't actually clean the sensor at all, it's the anti-aliasing filter over the lens, but we all call it the sensor. Cleaning is pretty straightforward. You have to be careful, but it's not a daunting proposition. Make sure the battery is fully charged, lock up the mirror and remove the lens. Hold the body facing down - so that the dust falls out - and use a Rocket blower. That's often enough. Stubborn dust may need a wet clean using Eclipse and pads, and there's a Lens Pen designed for cleaning the sensor too.There's a lot of information on these threads/the internet, or ask someone to show you how to do it the first time. This saves quite a bit of money, and the inconvenience of taking it to a dealer for cleaning.
