Visual Artifacts with Canon EOS 350 - help

Hello. I am new to digital photography. I recently purchased an EOS 350 D as my first D SLR. I've only taken a few pics but have already noticed some problems in my images. I have attached some pictures below but briefly there appear to be some odd particles/artifacts going on. At first I thought this was a digital problem in low light conditions but they have started to occur in slow shutter speed/good light and high aperture settings. This is a new camera only 2 weeks old. The only thing I have done is swap to a 300ml canon lens for testing purposes.

Byte size: ZERO | Content warning: NOT AN IMAGE

Byte size: ZERO | Content warning: NOT AN IMAGE

Byte size: ZERO | Content warning: NOT AN IMAGE

Byte size: ZERO | Content warning: NOT AN IMAGE

As a general rule, if the objects do not show up with wide apertures, but they do show up with narrow apertures, then that is one hint that they may be from sensor dust. Why not simply clean the sensor and see if anything changes?

---Bob Gross---

What I see in image #2 certainly looks like sensor dust. A good blower like hte Giottos Rocket should make short work of it.

http://www.pbase.com/c​opperhill/ccd_cleaning
That is what you need.

More UFOs. Dirty sensor.

They are indeed dust on the sensor - the proof is (1) they are in the same place on 2 photos (2) in the blurred photo the spots are not blurred. An air blower should be your first choice, read the manual re sensor cleaning (newly charged battery) and don't touch the sensor surface. Only if air doesn't remove them should you consider any more complex cleaning technique. If you have only changed the lens once, you have been either very unlucky or very silly (such as opening the shutter without a lens in place, to see what it looked like!)