35mm scan

Is it better to scan in a 35mm negative to the original size or to
select a target size like 4x6 before it imports into Photoshop? Or is
better to just scan in the 4x6 photo prints from the developer? The
file size must be under 100mb. The inkjet prints will be around 11x14.
thanks,
alex

For the best quality scan at the highest dpi your scanner will allow.
It is easier to downsample then to try to spread pixels across too large a
canvas.
This is not always practical if your scanner can scan at 4000dpi or more in
12 or 16 bit color.
If you really plan to print to 11x14 you should ideally have a scan of at
least 4000dpi to allow for cropping. Retouching is also easier when you have
more pixels to work with..
If you understand what you are doing you can get high quality prints of this
size from somewhat smaller scans, down to 2400dpi.
The way you phrase your question suggests you are inexperienced in issues
related to digital image processing and printing as well as use of
Photoshop.