How do I reduce the size of my photos at the same time. For example, I want all of my 80 images to be 70%.?

I take pictures with my digital camera, and each picture I take is over 2MB. I want to make it smaller. But doing it one by one is too tiresome. Is there a faster way? I do have Photoshop, but I don't know how to work with it. Thanks!

Irfanview, free program
http://www.irfanview.com

install program, open it, then press b then go from there

then I love Picasa as it is *magic* for a ton of other stuff, especially organizing and together with irfanview and Photoshop I need nothing else:
http://www.sleekbytes.com/picasa-google....

Look at the help system in Photoshop and look up 'batch mode'. Lots of photo programs will do this. I use a viewer called ACD See, and it will do it, so I bet Photoshop will.

In photoshop in the automation program.