It would also help you to know that different drawer glide manufacturers use varying intervals for their mounting screws. I'll use Accuride as an example. The first hole line from the cabinet front is set in 37mm. The next line of holes is set back 128mm from the first line of holes. The third line of holes is inset 96mm from the second line of holes. The fourth line is inset 128mm from the third line of holes, etc. Each set of glides comes with a sheet detailing the hole spacing for the specific glide. If you're going to use drawer glides, check out the glide's specifications and select the best spacing for the glides. Shelves can use the same line of holes; they're not as fussy as the glides. If you're doing shelves only, it's OK to go 37mm in from the front, 37mm in from the dado for the back, then split the difference. That doesn't work if you're using drawer glides, however.