The Arduino IDE provides a sample sketch with a simple program outline in a text window when you first open it. There are also a vast array of code samples under the File->Examples submenu item.

Arduino libraries, like libraries for other programming languages, help easily extend the range of functions available to users in the standard integrated development environment (IDE). They are ...

After writing a sketch to upload a .hex file from the Arduino serial console, [feynman] had a programmed ATtiny10, ready to be dropped into whatever astonishingly small project he had in mind.