I assume you mean wooden arrows.
#1 Lots of people us gasket lacquer for a sealer. I usually just use polyurethane. I like the kind with the stain in it for color, then I put 2-3 more coats of fast dry clear over the top, including over the cresting.
#2 I like Fast Fletch, which I think is just superglue gel. I have used superglue gel in a pinch. Again, there will be other opinions on this. I don't have much patience, so the Fast Fletch works for me. Some use Duco cement or FletchTight.
#3 Duco cement ($.96 a tube at Wallyworld).
I don't know if these are the best, but they work for me. Part of the fun of arrow building is in the experimenting though.