Cleaning my sensor

I took a picture of my white computer screen, ISO 100, f22, manually out of focus and got this:

https://www.dropbox.co​m …gslkgd6/0A3A416​9.JPG?dl=0

This was after I had the lens off, opened the shutter+mirror and attempted to blow anything off the sensor. From my naked eye I didn't notice anything on the sensor. Looking at the shot above, I can pretty easily find 5 ones that stand out.

What can I do to get these marks off the sensor? Should I just bring it into a store for a cleaning?

Eclipse and VisibleDust swabs are your friends.

The first thing to try is a Rocket Blower - I like the Giottos ones but brand is not important.
Remove your lens, point the camera at the floor and switch it to Manual Sensor Cleaning in the menu. Once the shutter is open use the blower vigorously and take care not to bump the sensor with the nozzle of the blower, I doubt it would do any harm but I don't want to find out the hard way!
After that switch off the camera, replace lens, switch on and try some test shots. Plain white paper is good as is a very clear sky - I am told these exist on some parts of the planet, just nowhere near me! Remember to stop right down as it will show any dust spots more clearly.
The above method clears most rubbish off the sensor, but if you have some really stubborn bits on there then a wet clean may be needed.