You can select certain parts to uv-map them in a separate skin, with Gutter Width and Maximum Stretch both at its maximum you can be quite sure to get that part layout in one piece. For instance the face including the front part of the ears, and in another step the back of the head, or an arm without hands (to assure that it is 'open' at each end)...
After that you can adjust the placing in the Skin Editor, fill the triangles with different colors paint a bit, and export the painted skin to work on it in Gimp or so, and import the finished skin later, again.
This is a fast approach, and sufficient, if you want fast prototyping and a cartoon style.
But, if you want to get good in modeling and skinning etc. you should learn a more sophisticated program like blender.