Building Tips and Tutorials. Ruthless KK Build Guide Link too .

I will also copy and paste in this post the hot keys that are listed in the Hot Keys thread that I posted in the second post

For the tools in build mode:
Eyedropper Tool (toggle): E
Hand Tool: H
Sledgehammer Tool (toggle): K
Design Tool (toggle): R
Wall Tool: B
Toggles Day/Night in B/B: L
Allow off-grid placement while dragging around an object: Alt
Toggle Grid: G
Cycle Between 1/2 tile and 1/4 tile grid snapping for object placement: F5
Flood Fill a single wall while placing wall patterns: Alt
Flood Fill floor & wall paint while placing floor or wall patterns: Shift
Toggle to 1/4 tile floor paint while placing floor tile patterns: Ctrl + F
Reduce Terrain Brush Size while Terrain Paint catalog is open:
Move Terrain Brush Softness Slider to the Left while Terrain Paint catalog is open: ;
Move Terrain Brush Softness Slider to the Right while Terrain Paint catalog is open: '
Toggle Terrain Paint/Eraser while Terrain Paint catalog is open: Ctrl
Move Whole House tool: U
Toggle Video Recording: V
Capture Screenshot: C

When you're placing objects in build mode:
Rotate held/selected object, block, roof, anything rotatable: < / >
Move object to next slot in surface with a slotted object selected and on a slot surface: M
Copy held/selected object on placement: Shift
Inventory held/selected object: Backspace
Delete held/selected object: Delete
Undo: Ctrl + Z
Redo: Ctrl + Y

For the camera:
Have the camera follow the Sim: Right-click on the Sim's portrait
Toggle Top Down View: T
Go to Next Floor Up: Page Up
Go to Next Floor Down: Page Down
Walls Up: Home
Walls Down: End