Should I pick the order in which pictures are shown?

Yes, if you prefer. No one knows better than you which order is the best or which makes the most sense. When giving the pictures to us, you can use a pencil to number the backs of them.
If you give them to us on a thumb drive, or email them to us, you can simply name each picture as "pic 01" and then "pic 02" and so on.  If you would like, we can also put them in our order, and "surprise" you.