I wanted a general propose lens that could cover most of my basic needs of photography. The L series of canon lens are first class lens and the EF 24-105mm f/4 L IS USM (in the 7D the focus range will be 39-168mm) is no exception, weather sealed, very fast and silent. Another that will be a great general propose lens is the EF-S 17-55mm f/2.8 IS USM, this lens is designed only for a camera body like the 7D and it will give an advantage in terms of the wide angle.
Just to recap some definitions about lens:
EF = Name of the canon mount
24-105mm = Focus range of the lens
f/4 = Largest apperture of the lens.
L = A special series of Canon quality lens
IS = Image Stabilized
USM = Utrasonic Motor (fast and quite focus)
This lens has for me the ideal focus range for almost every thing. It is "L series", meaning quality and with image stabilization, for now I have all I need to begin to enjoy the 7D.