Very Basics of Photoshop

Scale the image: ----> Image ----> Image Size

Crop the image:

Right click the crop tool on the left and use it to select part of the image

Rotate: ----> Image ----> Rotate Canvas

Zoom in, Zoom out: Control + and Control –

Select a circular area:

Right click the select tool on the left and pick the Elliptical Marquee Tool

Copy: Use the select tool to select an area ----> Control-C

Paste: Control-V

Add text onto images: Use the Type tool on the left

Free-form transformation:

Use the select tool to select an area ----> Edit ----> Free-form transformation