1-put enough special markers to your real scene and record it with your dSLR camera. make sure that there are enough contrast with the background and markers.
2-upload your footage to blender in movie clip editor.place all the markers in movie clip editor carefully.on the right side select your camera model under "camera data"
3-select all the markers ! and then track the footage (motion tracking begins)
4-after the tracking, check whether the markers move correctly. if there is something wrong, correct them manually.
5-select "previous frame" under tracking settings on left panel (blenderguru)
6-on the right panel under marker display select "search" in order to see the markers searching region, and you can arrenge it.
7-on the right panel under camera settings, select your dslr model in the presets if it is in the list. the sensor size etc will automatically be filled.if your camera is not in the presets list google your camera for sensor size and pixel aspect ratio.
select the focal length of your camera-if it is interchangeble then select the right lenght.use this length directly-not 35mm equivalent?-
8-click camera motion under "solve"
9-time to check the errors of the markers. click names and status under display (on the right)
10-make sure that the average error is under "3" .. ?
11-after everything is ok. you go to 3d view and select your camera- go to constraints and select "camera solver".you will now see that your camera will be moved according to your camera solver (tracking info of your footage)
http://www.blenderguru.com/videos/introduction-to-camera-tracking/ (blenderguru video tutorial)