Originally Posted by
dje
Richard
As others have said, you should be able to send them a full resolution jpeg image (ie max pixel dimensions) with a file size under 10MB if you select suitable quality settings for the jpeg compression. One thing to note is that the File Size shown on the Image Size Dialogue box is, as far as I know, the size that the file would be if saved as a PSD. This is quite different to the size if saved as a jpeg. You can get an idea of the size of the jpeg when you go through the Save As process.
If on the other hand, the web site is looking for images downsized for the web, you would be best to do this by simply changing the pixel dimensions in the Image Size box. Leave the ppi alone.
As a general comment, I've always found the Photoshop Image Size dialogue box very confusing and in my opinion, poorly designed. It appears (to this CS6 user) that it's changed a bit with the cc version but I'm not sure it's for the better!
With the Resample box unchecked, changing the ppi doesn't affect the pixel dimensions but it does change the XResolution and YResolution EXIF settings. This info may be used during printing from Photoshop, I don't know.
With the Resample box checked, changing the ppi does change the pixel dimensions but I'm at a loss as to why you would want to do this. It is far simpler and safer IMO to simply change the pixel dimensions directly.
Dave