Loud Squealing

[Guerrero707]

Need some help. Almost every time I start my 77 GMC C15 in the morning, when its cold, it stars squealing very loudly and it lasts a while, about almost a minute and when it finally stops its not gone if, I give it gas it starts squealing again, until it finally goes away. Also when I turn the wheels all the way to either side it makes that same loud squeal, but as far as I know the power steering fluid is full. If anybody can help it will be greatly appreciated.