Hi RJC - Welcome to PSG! Unfortunately, jargon and not knowing specific procedures in Photoshop is not your problem. It's much more fundamental: you first have to get a better understanding of the basic concepts involved and then you have to communicate what you have learned to the people/person who make up the constraints you are working under. For example:
1. The constraint you were given to keep the images at 300 dpi is essentially meaningless UNLESS you intend to print the images (vs show them on the web), AND you also specify the real-world dimensions (in inches or cm) of the final prints. If that is the case, then "dpi" is a useful concept. On the other hand, if you are going to post the images on the web, the "dpi" number that one can store in an image file is utterly useless. It's arbitrary and it's ignored. You could set dpi=2 or dpi=2000, and the image will look *exactly* the same. All that matters for web posting are the dimensions of the image in pixels (eg, 3000 px wide by 2000 pixels high).
2. The constraint you were given to make all images have a 1 MB file size is also very odd, at best. For example, I can have a set of different versions of one image that all are 1 MB in size, and they will all look very different because one can adjust various parameters to force an image to that image size, but the number of pixels will be different, the JPG quality factor will be different, the shape of the image may be different, etc. A much more reasonable way to specify the minimum acceptable quality of an image would be to specify the minimum acceptable pixel dimensions (eg, "no less than 3000 pixels on the short side") AND specify a maximum file size, not a "must equal" file size (eg, "each file can not exceed 1 MB").
My suggestion would be to discuss these "comments" in much more detail with the person who made them up.
Tom M
