This is a pretty good source:
http://users.erols.com/mwhite28/axis.htm
Loads of diplomacy maps:
http://www.diplom.org/Online/maps.html
Do your own thing, but here are a few golden rules from Flashy;
Decide FIRST if, and how much, map distortion you want. Western Europe and Japan are hopelessly small on a world map, so most of us use projections that exaggerate their size. It’s no good basing your outline on a real map, then discovering later that you don’t have room for enough territories in Europe.
THINGS TO AVOID AT ALL COSTS
1. Rio de Oro is in NORTH Africa. Mark that point. It is VERY important.
2. Moscow is in EUROPE. That is, nowhere near where official A&A boards put it. If you can live with such an outrageous falsehood as Moscow-in-the-Urals, go ahead. But in that case abandon any pretence of creating a historical map.
3. The Sinai penninsular is in EGYPT. There is therefore no need to complicate the board with having two territories controlling access to the Suez canal.
4. Countries such as Pakistan only came into being AFTER the war. You should NEVER include them, it is prefferable to use geographical terms such as “Western India” or “Indus Valley”.
5. India is a BIG country, in fact a sub-continent. It is the SECOND most populous country on earth after China. DO NOT follow the example of the uneducated and just lump it together as one territory worth a scandalously low 3 dollar value.
6. Regarding IPCS, an important factor is fuel. Using GDP figures gives you a starting reference, but remember that areas such as Romania, Caucasus and the Dutch East Indies were much more important than their GDP value owing to their crude oil production.