Adjusting the Resolution/Scale

I am trying to get a high resolution map for print so I am exporting via PDF. I am having difficulty working with the zoom. the increments by which it moves is to great. I was told to work with the scale feature to better control the zoom; but I apparently am not properly grasping how this is to be done. Thanks.

Maybe you can find some hints at http://wiki.openstreetmap.org/wiki/OSM_on_Paper

Also browse the OSM wiki for more information about SVG output etc.