Where do you find all the NPC'S on terraria?

I know how to get the clothier, the guild, the dryad, The hair stylist, the dye guy, the paint guy, the fisherman, and the goblin tinkerman. How and where do you get the other people? They are hard to find and google isn't giving me very useful answers. help anyone?

Here is a list of all the NPCs in Terraria, as well as when they can be acquired.

Pre-Hardmode

• Guide: Starting a new world.
• Merchant: All players combined have more than 50 Silver Coin in their inventories.
• Nurse: A player has more than 100 health and the Merchant is present.
• Demolitionist: A player has an explosive in their inventory, and the Merchant is present.
• Dye Trader: A player acquires a Dye item, or any item used to craft Dye, in addition to either defeating a pre-Hardmode boss or acquiring one Strange Plan
• Dryad: A Boss is defeated other than King Slime, Lepus or Wall of Flesh.
• Tavernkeep: Eater of Worlds or Brain of Cthulhu is defeated, and he is found and spoken to.
• Arms Dealer: A player has bullets, or a gun that shoots bullets, in their inventory.
• Stylist: Found and spoken to in a Spider Nest.
• Painter: After 7 other town NPCs are acquired including the guide.
• Angler: Found and spoken to in an Ocean Biome.
• Goblin Tinkerer: Found and spoken to in the cavern layer, after defeating a Goblin Invasion.
• Witch Doctor: Queen Bee is defeated.
• Clothier: Skeletron is defeated.
• Mechanic: Found and spoken to in the Dungeon.
• Party Girl: Chance of spawning after acquiring 13 town NPCs. (or as few as eight in the console version).

Hardmode

• Wizard: Found and spoken to in the Cavern layer in Hardmode.
• Tax Collector: A Tortured Soul is transformed with Purification Powder in the Underworld.
• Truffle: A House is built in an above-ground Mushroom Biome during Hardmode.
• Pirate: A Pirate Invasion is defeated.
• Steampunker: Once a Mechanical Boss is defeated.
• Cyborg: Plantera is defeated.
• Santa Claus: The Frost Legion is defeated, appearing only from December 15-31.

Other NPCs

• Traveling Merchant: 22% spawn chance during morning hours (04:30-12:00 in-game time) once two other NPCs are present

• Old Man: Starting a new world.

• Skeleton Merchant: Found randomly underground