If you can only buy one lens, then you might want a zoom that has a good wide to medium long range (like 18-70mm or so). The longer the zoom range, generally the less sharp (unless you spend the big bucks) but will give you a good starting range. If you can afford two, then one zoom like this, and one prime (50mm) because that will give you your sharpness, and depth of field for closeups if you want it. And now with magic zoom (1:1 or 1:2 mode on ML) you can zoom even further when you need it. If you want more lenses, I would look into old Nikon (Nikkor FD) lenses. They adapt to the canon body quite easily with a ring mount and are cheaper than new autofocus lenses. Getting good at pulling focus and aperture manually is a good skill to develop also. Hope that helps!