In the last stage of building bookcases. I've looked at some spec. on line, and all show a 3/8 inch deep dado cut for a 3/4 inch thick shelve. Is this deep enough for 24" long shelves that will have books on them or should I go 1/2 inch deep?
3/8ths is fine.....I am assuming that you are putting a back on this. You should glue and nail the shelf through the back. This will add support. Good luck.
You won't know if you can do something if you don't try.