Instead of opening one photo from a folder try this.

Launch Preview, it's in the dock, and then choose File > Open and navigate to your folder.
Select the folder and click Open.

Then, in Preview, go to View and check Thumbnails. This puts a list of thumbnails down the side of the Preview windows and hitting the left and right arrows, on the keyboard, you can scroll through them.

There are other options in the View menu.

That help?

P