Cut a pic into smaller squares - part 1

Start a new document Ctrl + N, width and height should be a little bit bigger then the picture you’re going to use to make it like a puzzle. Then create a new layer, press shift + F5. A new window appears, then at the Contest frame, select use Color and use these color #d5d5d5.

Press ctrl + O, to open a new picture, and load the picture you want to use. You will see only one layer, called Background. Click and drag that layer to our document. Press ctrl + T to resize the picture if u need it.
Now we have to cut the picture in many pieces. The best way to do it is to use guides, so we will cut it exactly how we want. To add a guide is simple, just click and hold the vertical or horizontal rule, drag the mouse, u will se a line that is a new guide, then place the guide where u want to. If you don’t see rules the go to View -> Rules, and I you don’t see guides go to View -> Show -> Guides. Here is what I’ve got:

Now using Rectangular Marquee Tool make a selection of the first square created from guides, and then right click on the selected square and choose Layer Via Cut. This way we will have a new layer with the selected part. Repeat these step for ever square created with guides...

Now, we are going to move and resize a little bit the layers on the corner, and make bigger some layers on the middle, so when we give some effects to them, they will like they’re out. I made a X on the squares I moved and resize. Here is what I’ve got.

Now apply these effects to the layers we moved and resized…

Drop shadow