RimWorld

General

Don't be afraid to save scum when you first start out to learn the mechanics. Even if you do, you're still going to fail quite a bit. That's just Rimworld. Not every story has a happy ending. Learn from what went wrong and send some more unwitting losers down to try again.

Raiders don't generally destroy colonies, heat waves do. You can make a masterpiece of a base and it will still get destroyed because all your food spoiled in the heat and everyone is getting heatstroke in their masterfully decorated rooms because it's 500 degrees F outside.

Research is really important. Make sure you've got a research workstation set up and that somebody has research enabled on their job list. By default it's the lowest priority thing, so you might want to tell your researcher to not clean or haul (or alter the priorities in manual mode) so that they put more of an emphasis on doing it. One of the techs you can research adds a new power-dependant research bench that's much better (and another one later adds a separate object called a multi-analyser that you need to place in proximity to the research bench to learn advanced techs).
- Nothing is stopping you from building two research benches and having two people do research at once. Or three. You get the idea.

With hostages and pod crash landings, 'rescue' means they leave after you treat them, to keep them in the colony you have to capture them (in a room with bed set to allow prisoners) and convince them to stay.

Dwarf Fortressing into a mountain as a starter base sounds like a good idea but in reality it takes forever to mine out rooms and when you finally do the whole place will be dark and filthy. Dirty rooms give a negative mood, if your whole base is dirty then people will go insane pretty fast.

Fire is bad. Wood and (confusingly) steel constructions will burn. Stone walls don't. Research and build a stone-cutting station to make usable blocks out of all those damn rocks lying around the place and use them for exterior walls / things that need to be fireproof. Make sure to change the selected material when building.

Hauling is a huge time sink, so be thoughtful about stockpiles. Having a priority stockpile set at a high priority near a crafting table will save a lot of time in the long run. Similarly, make sure it's a short walk from your fields to your fridge.

A clean work area is a productive work area. Having crap on the floor slows down work/research. Keep those workshops/labs tidy, and don't neglect the Cleaning task. This is especially true of the kitchen. Any dirty room is ugly, but a dirty kitchen leads to food poisoning.

Chairs. You know what people need when they're at a workbench, slaving away at a lengthy project? Somewhere to fucking sit. Put a chair (face it the correct direction) at the interaction spot and they'll be more contented. Hell, if the chair is of a high enough quality, they may actually gain Mood from building/cutting/sewing/etc.

5x5 rooms with only a bed are just big enough to avoid negative moodlets for being cramped.

Make like Matt Damon and grow tons of potatoes as soon as you can, they are the most reliable source of food and won't spoil if they are in your freezer.

Make perimeter walls with only one entrance, at least for early game raids the enemies will only go for the entrance and you can funnel them in.
- Don't worry too much about 'future-proofing' your walls by giving yourself huge amounts of room to expand, you can always deconstruct them and reuse the materials later.

The little automated gun emplacements aren't that strong, but enemies prioritize them so not only does it help control the places your enemies attack, it keeps your colonists alive a little longer.
- They also have a chance to when they have sustained too much damage. This isn't necessarily a bad thing - the AI tends to go after them first, so a lone turret far out in front of your defenses may draw raiders in close for the fireworks. If eight raiders surround that turret and beat it to death, you're looking at eight dying or dead raiders after it goes off.

When someone does go crazy you want to make sure you tell your remaining colonists to drop their weapons before taking down the madman, bruises will easily heal but cuts and bullet holes will not.

Raid difficulty is heavily based on how lavish your settlement is. Find some gold in them there hills during the early game? Leave it there. It's safer if it needs to be mined in order to be stolen anyway. If you put it in a stockpile or build gold tiled floors out of it or something, you'll raise the overall value of your settlement. Unless you've got colonists on the brink of a major breakdown, stick with a spartan lifestyle for the early - and maybe even mid-game.

If a faction is just pissed-off enough to be hostile toward you, capture some of their attackers, heal them, then set them free. Each one that gets off the map successfully gives you +15 with that faction. After a couple of jerks take off walking, the faction may be so grateful to have their people back that they stop attacking you.
- Before letting them go, consider giving them peg legs and wooden hands, ~~especially~~ even if they don't have any missing limbs. It's a great way to train your surgeons.

Nutrient Paste Dispensers are bugged as hell and not worth it in the first place even if they did work as intended. Slap together a makeshift kitchen (or campfire if you're really in need) and cook things instead. The game even tells you that nobody likes eating nutrient paste, so give them real food instead.

You need to build a freezer (a room with AC unit(s) set to below freezing) to store all your food, medicine and animal corpses. Adding a small airlock room (just a short corridor with a door on each end) as the only way into your freezer will help keep the cold air in there and make it more energy efficient. Additional wall thickness also adds more insulation and being in a cave or mined out area is also more insulated than an external structure that you built yourself.
- For purposes of thermal conductivity, all varieties of stone seem to be equal.
- Building your base in a mountain and don't have a solution for your cooler/freezer? Build a corridor that will bleed the heat out to the open. Don't think of it as an impassable area - colonists can pass through it to get from one place to another just fine so long as it's not ridiculously hot. Crossing over one or two squares of 120F heat isn't going to hurt anyone, so don't think of them as "ducts," but rather "really warm hallways."

Batteries and several other electronic things will explode or short out if they're rained on, so you'll want to make sure they've got a roof over them.

Batteries in particular will also explode because fuck you regardless of where they're stored. I like to keep them in a little form fitting stone-walled cell to keep them from burning my house down.
- The larger the circuit, the worse the explosions, so consider having separate parts of your base on completely separate circuits, if you have enough ways of generating power.

Lights are great for morale, but use an absurd amount of power. Try to only use them in high traffic areas.

By default any power consuming thing you build draws power regardless of if it's being used or not, so make sure you turn things off if you're not using them at the moment.