Most - but they do have a forum for boardgames/hex and counter style wargames.
Mind you, a brief skim indicates the advice is either photoshop/open-source alternative or Hexographer
As for the differences between RPG maps and wargaming ones, I wouldn’t get too hung up on them. It depends on the RPG.
You would presumably be looking more for advice on creating the old-school style world map in hexes (which after all directly came from wargaming).
I mean - presumably all you care about is that you can create hexes at the right scale and plunk terrain down onto your hex map as you choose?
Or you could just take any map that is at the right scale and pop a clear overlay with hexes printed on over the top. Each hex takes the terrain type that the majority of terrain covered by it consists of.
By the way, there appears to be a newer version of the OgreMap software:
(found via the forum at SJ Games)