What i used on my maple veneered speakers i made was:
1 - Danish Oil - applied with a cloth and then cut back with very very fine metal wool (Grade 0000) - repeated x3 - this helps bring out the grain and slightly deepens the colour.
2 - Liberon Fine Bison Paste Wax - applied with cotton cloth - left and then buffed off with a lint free cotton cloth.
This has produced a lovely finish (shiny but not in the same way as a varnish) and also surves to protect the veneer from drying out.
Hope this helps
nb - before applying any of these finishes it is always a good idea to use a tack cloth to get rid of any traces of dust