Making a photo gallery using php...

Hi... This is my first posting here. Please excuse any questions which seem stunningly simplistic to you!

I wish to have a photo gallery on a website which will be different each time it loads. Firstly is that possible (and easy) with php?

Is there an easy (and I mean simple!) installation guide and 'How To' article available anywhere on the site? If so could someone provide a URL please?

I really do need a step by step guide to doing this.

Any help would be much appreciated.
Thanks
Colin