Minecraft creating texture pack?

Hi on minecraft i wanna create a texture pack but i already know how but like on the paint apps i don't know how differentiate the legs from arms and i keep messing up is there a website that lets me create texture packs in the way that you make skins on minercraftskins.com? Cause i wanna make horses cars and the pigs baby's and the cows baby pony's and chickens chicks and you know…