(Everything said below is my opinion, based on my experience with the lens.)
Kit Lens
PROS:
Light
Comes with camera (unless you're just buying the camera body)
Has a mirror stabilizer
Wide angle
CONS:
Feels cheap, like it could easily break
Picture quality is poor
(which doesn't mean you won't take great pictures, there's just an obvious difference in quality when compared to other more expensive lenses)
Rather small zoom
Lowest aperture is 4.0
CONCLUSION:
While the kit lens is considered 'cheap' and has 'rather poor' picture quality, that doesn't mean that you can't take incredible pictures with it. Sure, it's not typically a professional's 'go-to' lens, but when you're first starting out, it's perfect for your needs. Here's a link to a blog by Zhang Jingna, a professional photographer who started out with a 350D and the kit lens it came with. She has proven with her photography that you can take amazing photos with a kit lens. So as you add lenses to your collection, don't throw your kit lens away. =)
http://blog.zhangjingna.com/2010/10/equipment-and-where-money-comes-from.html#.V5phMvkrKM8