i created a 3d model in zbrush and detailed it…but when i press uv chek it converts to entirely red…that seem to be the uv’s are overlapping now what should i do plez tell me 
change his UV’s…
tool>texture>AUV or GUV.
If you want a good UV layout, then you need to manually lay out the UV’s
roadkillUV is where I start for anything organic.