IPalindromel is correct; you can find a version of Adobe .PDF Printer for System 6-9 online. Select it on the Chooser and then print to it and and it create a .pdf file of the job you are working on.
Going into Image and then to Image Size, you are changing the entire image size and resolution irreversibly. Best to save the original file before such a change and then save a second version and give it a different name - like "File Name-Printable.psd". Then work with the second file. This way is something were to really mess up, and you need to revert to file's original image, you can just reload the original file.
I know there are a set number of UNDO's in PS, but if you exceed them, you might not be able to go back to your original file. this way you saved a copy of it or "Just In Case."
Going into Image and then to Image Size, you are changing the entire image size and resolution irreversibly. Best to save the original file before such a change and then save a second version and give it a different name - like "File Name-Printable.psd". Then work with the second file. This way is something were to really mess up, and you need to revert to file's original image, you can just reload the original file.
I know there are a set number of UNDO's in PS, but if you exceed them, you might not be able to go back to your original file. this way you saved a copy of it or "Just In Case."