Try this tutorial instead. http://cgi.cse.unsw.edu.au/~cs4411/wiki/index.php?title=OpenCV_Guide
but the tutorial you identify is quite good. I used it to get my haar classifier sorted out.
The facedetect sample code included in opencv 2.1 distribution is a good example for checking the resulting xml file. (I use python)
I found several problems with the supplied help applicatoins.
1. createsamples will not read a description file with more than 8 samples from the same image - manually break your relationship file up into several lines with no more than 8 rectangles per image.
The haar training would not continue if my .vec file was made with images of width and height > 24 pixels
Main issue with haar appears to be that it is not invariant to scale and you need thousands of test images - which is what the createsamples program will help you to do with single images but will not if you have a description file of individual sample images. Hence the tutorials extra code to allow createsamples to be called many times and for the resulting vec files to be merged into a single super vec file.