When giving talks at camera clubs i often get asked about lens selection and particularly for shooting street photography. This latest video from Sean Tucker gives a nice insight into lens selection and is well wort a look. One point i would raise personally is you will probably always feel like you have the wrong lens on but you need to understand the lens and be flexible, zoom lenses do allow you some wiggle room.
A question often asked when I deliver talks - What Focal Length Lens to use for your STREET Photography?