Not many people participate on these forums, I hope you haven't given up on the game already.

It's pretty much a standard 4X turned based game.  I can't point to a tutorial, but I hope these points help.

The basic currency of the game is mana.  This is determined by how many magical shards you control.  There is a spell to increase the mana generated by a shard, but ignore that for now, concentrate on controlling shards.

You control shards by expanding your zone of control to get them within your territory, and then building a shrine (right click on the shard and select build).

The mana the shards generate is split into 3 uses.  One third goes to researching spells, one thrid to building your sovereign's level, and one third to mana that you can use in combat or strategic map spells.  You can change these proportions by clicking on the circle in the upper left and moving the pointer there.

You expand your zone of control by expanding your cities, founding new cities, and founding outposts.  Founding new cities and outposts requires you to train settlers (some quests also allow you to acquire settlers).  Only they have the ability to found outposts and cities.  Cities can only be settled on fertile tiles.  These are indicated on the strategic map by the presence of grain icons.  Outposts can be founded on most tiles, although there are exceptions (swamp, mountain, etc).  

You expand your city in three ways.  One, by building up enough food resources to increase your citizens.  Second, by increasing your production.  Third, by casting a city enchantment spell.  When a city levels up you can choose a new tile adjacent to the city.  The tiles are marked with grain icons, hammer icons, or enchantment icons.  the grain icons increase the rate of city population, which controls how cast the city levels, the hammer icons controls how fast the city production increases (how fast you can build new improvements) , and the enchantment icons control how many enchantment spells can be cast on the city.

While your cities are expanding, you need to explore with your army, add reinforcements by training new units in your cities, find new heroes to add to your army (by liberating frozen heroes or by getting heroes from other minor factions by allying with them), doing quests with your army, collecting additional resources like metal and horses by founding outposts and building on the resources, and adding equipment to your units by using the forge and found armor and weapons.

As your sovereign levels up, you can choose abilities to increase the size of your army, cast new spells, and use other abilites that vary for each sovereign.

Finally, after you have located the Sorcerer King's palace, and built up your forces so that they are strong enough to defeat him, you march into his palace and kill him.  (There are a couple of other ways to win but I'm being brief here).