I'm sure McCreed meant use CA to glue the veneer into place. But that's a very small gap to fill with veneer, which will need to be wafer thin. For the nut itself, PVA or Titebond to glue the whole length of the nut. If you use CA, then just a couple of small drops on the bottom of the nut. Too much, and you won't get it out if it needs replacing.

But you'll probably find that any nut you get will be too tall to start with. They really are designed to have the slots cut down to height with nut files and then the excess height above the slots filed off and sanded smooth. But good nut files are really expensive, so the normal kit method is to keep sanding away at the bottom of the nut until the slots are at the right height. So don't glue the nut in straight away otherwise you'll be right back where you were. String tension will keep the nut in place when setting up, so don't glue the nut in until you are happy with the neck relief, string action and string height at the first fret.

There isn't a one-size fits all solution for nut slot height, as it all depends on how much neck relief you like and what action you like as to how high/low the slots will need to be above the fretboard to give sufficient clearance at the first fret. And if you set the guitar up for slide, you'll probably want a higher nut slot height to avoid the slide pressure fretting the stings over the first couple of frets.

The pre-built forum software sets a maximum limit of five hosted pictures per post (and one embedded video link). If you want more, then you'll need to host elsewhere (say Flickr) and link to them. I use a mixture of site hosted and remote hosted pics. Note that if remote hosting, the link needs to be of the image itself (so the link should end with .jpg or .png), and not of the page the image is hosted on, which won't display anything.

Otherwise, all as the two posts above.