How to control the zoom in and zoom out? I am doing a model and the speed at which I am zooming in and out is very fast. I mean one scroll and I am inside the model, looking at faces and one scroll in opposite direction, my model appears in complete ISO view.
How to control this? Any settings are getting messed up?
Hold Ctrl + click and hold middle mouse button and move the mouse forward/backward for more precise zooming.

Left Alt + click middle mouse button on the object you want to focus on to reset the zoom-focus on this object.