The Raspberry Pi usually boots and runs from an SDCard. Preparation involves installing an Operating System (OS) onto the SDCard and then configuring various options. There are many customised versions based on Linux available online and a good place to start is the raspberrypi.org website itself. One of my first projects was the OSMC (Open Source Media Centre).
The size of the installed OS image can vary - some will fit onto a shitty little 4GB SDCard, although I would use a bigger card for more 'growing room' (updates, etc.). I grabbed a handfull of 16MB SDs (the smallest available!) from Officeworks for $15 each, so I can swap in different cards to boot to various systems, with space to spare. But that's just me, I can be a bit fancy sometimes..
Note that some RasPi models boot to a full-sized SDCard and some use a MicroSD. I would recommend buying a Class 10 MicroSD with a full-sized SDCard adapter for maximum flexibility and maximal quality. For the ultimate lowdown on how SDCards are classified, consult the definitive www.sdcard.org
The OS image file may come in a compressed format such as .zip, .tar.gz, ZIP64 or similar and usually needs to be extracted to use the .img file, so an unzip tool will be required. Skip this step if you use Etcher (below), which should handle the unzipping itself. The following zip tools support most compression types:
Shove an SDCard into a card reader on your computer and format it to remove any crap (back up any files on the card you want to keep beforehand). An SDCard formatter can be obtained from the SD Association website.
Finally 'write' the image to the SDCard. This usually involves a third party utility to get the job done. Etcher is a graphical SDCard writing tool that works on Mac OS, Linux and Windows and is very straightforward to use. Etcher also supports writing images directly from the zip file, without any unzipping required. Smart.
.zipfile to write to the SD card
After Etcher has done its thing the SDCard is ready to plug into the Pi. Plug in USB keyboard, mouse and monitor, plus sound and Ethernet as required and power up.
Alternatively get the thing to boot headlessly without such pretentious peripherals.
First job is to run raspi-config to finish basic setup after the first boot..
Now the fun starts..
AndyM | Updated July 2019