Assuming you've grabbed both the mod and the map and also assuming you have disabled other mods if you are experiencing any crashes...
-- Use the Mod, not the "Experimental" version if it appears in your list of mods. In the very near future, major updates that will break saves will have its version listed and long SP and MP games can use the version they began on without concerns about things breaking.

-- Start a New Game.
-- Load the map.
-- Select your nation(s)
-- Fill all available nation slots with random nations (hold down n to make this easy).
-- Create or load your custom Pretender.
-- Set your preferred options such as magic sites, score graphs, story mode, hall of fame, etc.
-- Set your Ascension Point Victory count. (There are 100+ possible points currently) A good number for a medium-long but completable game is around 11-15.
-- Reduce the number of random thrones of levels 1, 2, and 3 to ZERO. Skipping this step will result in vanilla thrones spawning on top of custom thrones and other weirdness.

TIPS
[Starting Position] Many nations have multiple starting provinces, some of which are far away from their capital. Waterdeep, Amn, Cult of the Dragon, the Shaar, the Zhentarim, Calimshan, and a few others. Use the 'n' key to skip to units without orders at the end of each turn, especially the first one, or you may realize later that you had a whole province and a bunch of units you didn't know about.

[Slaves] Lots of nations rely on cheap slave units in the lore and in the mod - especially in the old empires of Chessenta, Unther, Mulhorand, and Thay. Calimshan and Amn also have easy access to slave troops as do most of the Underdark nations. This is a huge resource.

[Dragons] Several nations can summon dragon eggs, which take time to hatch and mature. They also cause problems as they grow older, such as unrest, increased upkeep, and feeding off your population. If you're up against a dragon-fielding nation, best get those eggs before they hatch. There's also a chance to 'seduce' them with certain commanders. While the spells that produce eggs are only available to a few nations, any nation with a mature dragon can have them engage in their mating ritual once per turn.

More to come...