As an add on question - what resolution is best for doing UV Maps?
There’s no “best.” The resolution you choose depends on the maximum amount of the screen (in pixels) the texture will occupy. If your texture will at maximum occupy a 640-pixel wide area of screen real estate, then for best appearance that part of the texture should be at least 640 pixels across. Note that when a texture wraps around the object (like a head), you’re only looking at part of the total image. If the above example were for an image wrapped all the way around a head, the entire texture would need to be at least 1280 pixels across. So there’s some planning involved in making great textures.
Also note, many graphics cards work best with square images whose pixel dimensions are exact powers of 2 (eg1024x1024, 2048x2048).