Actually what you really need to use the SDK, besides some programming knowledge of course, is some insight into how the UO client works. Once you have an idea of what you want to do, it should be pretty easy.
You need to find the world location of the client, the best guess is the Client class. You don't really need documentation for that... also if you look in the SDK you see a class called Map with a static method called GetImage. That's all pretty easy to figure out.
Use the object browser to look at the classes. They are all named after what they represent. Hue is a hue, Client is the client, and so on...
Also if you need to display the map, try my map viewer (which is on my site, WWW button below).