Guide:

First you should reach a certain level of strength in Minetest, best above stone tech level, if you are playing Single Player or without NPCs to fight for you. 
I recommend to use 3D Armor.
Brace yourself for your first contact with the plunderers, normally they come in a pack of melee and range and you can only beat one of them, 
if you manage to separate a plunderer from the group.

If you are lucky you will be victorious and gain your first item for attracting people. This could be an Anvil, Weaponstand, Feeder, Villager Bed, 
Mineshaft or First Aid Node.

If you haven't build a building yet, now is the time to come, because you need a wooden floor to place your gathered items on. 
All 5 default wood types (apple, acacia, pine, aspen, jungle) are suitable for a building floor and will spawn different looking people.
After your first citizen has spawned, he is trading with you, but wont stay near your building. You first have to “tame” him or her,
every profession likes and needs different things:

Blacksmith: Farming Dishes
Farmer: Coal Lumps
Doctor: Mint Tea
Miner: Hemp Oil + Hemp Leaves
Instructor: Gold Ingot
Warrior: Farming Dishes
Villager: Farming Dishes

To get items from them, you need to trade the following things with them:

Blacksmith: Gold Ingot
Farmer: Gold Ingot
Doctor: Gold Lump
Miner: Food (e.g. cooked dishes from the farming mod)

After you satisfied your new resident, you can tell him or her to stay at place. If an enemy will raid your town and kill someone, 
you will find a wooden cross. You can burn it in the furnace, or bury the dead, but beware: Do not forget to bury the citizens 
in soil which provides the corpse the chance to rot, otherwise, a surprise will occur at night...

To be successful you need to mine a lot of gold and use the trading system wisely, because its based on chance.

There is some more stuff in this mod, but this will not be revealed here, the basics are enough to play successful, the rest should be discovered by yourself.
