As mentioned before, honey is almost completely fermentable and so it tends to give you a very dry alcohol addition and really doesn't contribute to a honey flavor in the end product. Gambrinus honey malt will give you more of the honey flavor you might be looking for. I recently made a honey wheat beer that used 2 lbs honey with 1/2 lb honey malt. I also added 4 oz carapils to counteract the dryness from the honey.
So if you wanted to add a little honey flavor to a SNPA recipe, then I'd suggest adding 1/4 lb. honey malt and work from there. Keep in mind for extract recipes, any honey addition is going to increase OG, while addition of honey malt to steeped grains won't really contribute any meaningful fermentable sugars.
As far as timing of honey addition, there are several ways to do it and each has their own advantages/disadvantages. Boiling any aromatic/volatile compound will result in lower levels in the end product. However, honey has wild yeast, bacteria, insect parts, etc. that would require some form of sterilization. So you can add it at the boil, you can pasteurize separately and then add to wort, or my preference is to add the honey at flameout. As mentioned before, learning by experience will be way more informative than reading about other people's preferences. Good luck!
Marc.