Now my 2c

1/ you don't need L glass.
2/ L glass will improve your pics over Most other cheaper lenses - regardless of full frame or cropped. - cropped sensors today are better res. than full frame use to be.....
3/ if your bugget can streach to a 24-105 you would find it to be a great lens for what your after.

Just to let you know I am in favour of the 24-105 ( have 50D & 24-105 ) but that doesn't mean you need one when starting out.

if bugget permits
I suggest you try one ( or similar 24-70 etc. ) in the shops, put it on the camera and take a couple of pics

as to a more affordable lens - i just brought the Nifty Fifty ( 50mm f/1.8 ) its very sharp and am having fun with it $129 - you could get one and use it while figuring out wich lens next
as above - For good reviews see: http://www.the-digital-picture.com/