How to Combine or Merge Photos in Adobe Photoshop

1. Open a new document in Photoshop
2. File --> Place --> Select picture 

How to fill a shape with a colour in Photoshop CS2?

1)"control+click" on the layer of the shape that you want to fill in. 

2) Once your shape is selected (has little marching ants around it), create a new layer (control+shift+n).

3) click on the foreground color selector, pick the color you want, and click "OK" .

4) Fill the selection with your color (Edit > Fill) or Shift+F5 select your foreground color as the choice for the fill.