If you are new to SLR photography, I would suggest starting with a prosumer zoom, then find out what you really like. You can then complement your first lens with either fast primes or "L" zooms. I never recommend the kit cheap zooms.
The Canon EF lens lineup can be broken down into five categories. The following is my quick summary of this lineup:
1) Kit zooms (18-55EF-s, 28-80, 28-90, 28-105/4.5-5.6): All cheap, with plastic mounts, about $100, all make good paperweights.
2) Prosumer zooms (28-105/3.5-4.5, 24-85, 28-135IS, 75-300 and 100-300 lens): Decent quality, with USM motors. Costs $150-$300 for the non-IS lenses, about $400 for the two IS lenses. The optics are generally very good, but the xx-300mm lenses grow “soft†beyond 200mm. These lenses are a clear step above the kit-zooms, and definitely worth the extra money.
A note about IS: Image stabilization is a tool like any other. It will stop your “camera shake†when you shoot a slow shutter in dim light. It will not stop the subject from moving. A 1/10th second shot with IS is fine for a landscape, but bad for a bride moving down an aisle.
3) "L" zooms: Creme de la creme. A full notch above the prosumer zooms but very pricey. The $1300 2.8 versions are generally on par (optically) to the $600 F4.0 versions. Built quality is also better.
With the zooms, it boils down to how much you want to pay. I would *never* recommend the kit lenses under any conditions. I have seen a few people question if the higher resolution of the "L" glass is visible (vs the prosumer zooms) on a 300D/10D sensor.
In the telephoto realm, all of the prosumer 75-300mm lenses are somewhat weak, and the 70-200/4L is an excellent lens. I can definitely see the difference on my 10D. Many would suggest skipping the xx-300 prosumer zooms and saving for the $575 70-200/4L as a photographer’s first “L†lens.
4) Cheap primes (24/2.8, 50/1.8, 85/1.8 ): Premium optics in cheap body lenses. Despite lack of USM motors, Full Time Manual Focusing, and in some cases metal lens mounts, the sharpness matches the $1300 F2.8L lenses. Flare resistance should be superior. Prices range from $70 for the 50/1.8 to $400 to the 20/2.8
5) "L" primes (24/1.4L, 50/1.0L, 300/2.8L): Fast glass! Expensive glass! For $1300+ you get top notch optics that you expect, and ALL the bells and whistles. The wide angles are reportedly not quite as sharp optically as the cheap primes. The telephoto primes are some of the best glass in the business.
My kit: 24/2.8, 35/2, 50/1.8, and 70-200/4L. Less commonly used stuff in my bag: 28-105/3.5-4.5, 75-300.