These links have some usefull instructions on weathering:
http://www.ipmsstockholm.org/magazin...weathering.htm
http://www.culttvman2.com/dnn/Portal...weathering.pdf
http://www.armorama.com/modules.php?...rtid=34&page=1

Also, look for pics of 1/35 scale tank models on the net to see how they are weathered. A quick answer to your questions would be:
- whitewash - applying a coat of very thinned white paint which cloud and lighten the main color (make sure to test the resulted thinned paint on another similar surface before applying on the model)
- drybrushing - is used for acsentuating highlights of outer edges of surfaces - goes with a lighter shade of the color of the surface you will drybrush - lightly dip a brush in the paint, wait for it to dry off to the extent that it still leaves marks but it cant be used for smooth painting, and brush the edges in fast strokes. Again better test and get used to it before applying on the model.
- dull coat - yes, it is a transparent mat coat,either sprayed or brushed on to remove the glossyness of the surface.

Pitty I have no photoes to show you of how these things look at the end, but do a google search on weathering and you will come up with a lot of information. Weathering isnt easy but its probably the most fun part and gives uniqiueness to your model.