Body
Seems like you're going for photo-realism over an exaggerated and toony style, so get decent anatomically correct base models with clean topology to build and animate from.
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MakeHuman is an open source tool for making 3D characters. The topology is clean, has good body morphs. And you can export the models into Blender very easily. Use this great and free tool right now.
Hair
Seems like you're on the right track here, but your render/quality settings are not correct. You need thousands of guides instead of hundreds. Blender hair and fur is actually a strong point, you should have fantastic hair. Check out this tutorial:
Clothes
Clothing is not an extrusion of the body underneath. It's not an orange peel. It's 3 dimensional, has weft, waft, stretch and folds. If you want a decent clothing solution, try Marvelous Designer. It's expensive and the industry standard and I personally recommend it. You make fabric patterns, stitch them together, drape them over a static or animated model and then simulate the cloth.
Render
White dots and an overall graininess means your lighting rig is not sending out enough samples for your surfaces. You need to double+ your lighting rays, up your AA etc. You really should be rendering out passes and then composing them in Nuke/Photoshop for color control and general tweak-ability. You'll be able to then tweak the lighting, make the shadows darker/lighter, correct over-saturation/lighting etc with a few clicks in photoshop instead of having to go back and re-render.