there are loads of posts on pressure cleaning here, just click back a few pages, also have a look at scsf there forum is used by alot of the members on here.As for training see if you can find a local guy and offer to do a day or two for free to pick up the basics. The only training i did was for graffiti removal which was a one day hands on course with a company called "graffiti hotline" they are very good and will also help you to price up jobs, they are also used by alot of local authorities to train their staff