all the above advice is sound, but as with any optical device you must ensure you do not look through the actual viewfinder of any digital camera, this includes compacts , however the very nature of an slr means you must use the viewfinder to compose the image, so os be very carefull, as for damage to the sensor it shouldnt harm , but you can never be sure
there will be no problem looking at any digital compact screen ( live image ) of the sun as the output of the screen will not be bright enough to damage your eyes, bit like watching welding on the telly, if you see what i mean
at the end of the day a damaged sensor can be replaced, the same can not be said for your eyesight...........
MyPix