I bought this camera in the summer (actually bought it in the US where it is known as the digital rebel XSI). I was always a keen photographer without the hardware to work with - previously used a standard Nikon Coolpix digital camera. This camera is great, the clarity is so much better on pictures and the world really is your oyster with an SLR, and even more so with a Canon.
The kit lens you usually get with it (18-55) is pretty handy for starting out and then you can add to it as required.
Beginners will unboubtedly start by using the full auto mode which basically chooses the shutter speed, aperture, ISO and all other settings for you, also it will decide whether or not you require the flash (which automatically pops up). This is a good setting and a great starting point for those novices to SLR's. The other scene modes are portrait, landscape, close-up, sports and night portrait. Then, once you are more comfortable with the more technical aspects you can use AV (Aperture priority) or TV (Shutter priority). The "holy grail" is Manual which I have not ventured to yet, this is where you decide all the technical aspects of your shot. There really is far too much on the camera to get your head round at first and so I'd suggest you do what I did which was to buy a companion - "Canon 450d Companion" - by Ben Long has served me well thus far in explaining some of the new features I had never used before.
4 months after purchase and I am still delighted with it, many people have commented on my pictures which is always a nice feeling.
I would recommend the following to add on to your camera:
Lens hoods for each lens
UV filter for each lens
Canon 55-250mm telephoto lens. On Amazon for around £180 (Great purchase and excellent coverage)
Canon 50mm Macro lens - On Amazon for around £90 (bargain)
A good sturdy camera bag - Lowepro
A tripod if you are going to be taking night photos without the flash to avoid camera shake.
If you are far enough along the line to have decided to get a SLR - This is a brilliant camera to get you started.