In this toturial we will learn  very basic and simple steps to make the effect of pencil drawing to our images .
1- pick the picture you want to pencile draw it .
We need two layers one for the image and the other will be white color .

2- with the image layer selected . change the Layer blending mode to Luminosity

3- the next step is to add the filter find edges to our image
go to Filter>stylize >Find Edges

now your picture should look something like this

4- Pick the Eraser tool and erase the unwanted shadows which depend on ur own view , or how you want your final work to look like.

You may also change the opacity of Eraser tool if you dont want to delete the shadow and just want to make it more light.
or also use Brush tool to add more shadows . which i leave it to you
Hope you enjoyed.