This will guide you through installation and configuration of a Raspberry Pi B+ with the Raspbian operating system so the device will be accessible on your network. Readily available for around $35, the Raspberry Pi ecosystem is fast-becoming a hobbyist workhorse.
Download Raspbian zip file from www.raspberrypi.org/downloads/raspbian. This example uses "Raspbian Buster with desktop" of February 2020.
Download the Etcher program from www.balena.io/etcher. Etcher will write the OS zip file image to the SD card.
Insert an 8 GB (or more) microSD card in to the card reader on your Windows PC. This example uses a 32 GB card. In Windows Explorer you should see the SD card.
Use the Etcher program to write the zip file OS image to the SD card.
After writing the image, the SD card will be unmounted. Physically eject
the card from your PC, then reinsert it. Determine the drive letter by
looking in File Explorer.
Let's tell the OS image to allow ssh login. Press the Windows Start button, type
and start the Command Prompt application.
In the command prompt, go to the drive letter of the SD card. In this example, type
Create a zero length file named ssh. In the command prompt, type
type nul > ssh
If you will use a hard-wired ethernet connection from the device to your router, you will not need to configure wifi. To configure wifi, create a file named "wpa_supplicant.conf" with your wifi connection information. The file should only have the suffix ".conf" and the contents should not have Windows-like newline characters. It is important that newline characters are not added to this file. It should be a plain text file. Add the following to the wpa_supplicant.conf file.
Type exit to leave the command prompt.
In Windows File Explorer, right-click on the drive and choose EJECT. Physically eject the SD card from the PC.
Plug in the microSD card to the device, and insert the power connector cord in to the device. Don't yet plug it in to power.
Open your router configuration page, and look for the area which shows the current connections. You will looking for either a new DHCP client or a new MAC address. Now that you have opened your router configuration to the appropriate page, plug in the wall power for the device and turn on the power switch.
Watch the router page for a new connection. If using wifi and it doesn't connect to the router, use the ethernet cable method. Note the IP address.
Press the Windows Start button and open a command prompt. In the Windows command prompt, connect to the device using the IP address as seen in your router.
Accept the key fingerprint warning by typing yes.
The password is
You should be logged in. Change the password.
Modify settings such as locale language, host name, and maybe enable VNC. Start the handy configuration tool. I changed the locale and the host name.
$ sudo raspi-config
If wifi didn't work or you want to enable it, become root and edit the file.
$ sudo su
$ sudo vi /etc/wpa_supplicant/wpa_supplicant.conf
Reboot the device.
$ sudo reboot
The router page will show the new host name.
For installation of an operating system on bare hardware, this was a smooth and pleasant experience. The teams who put together the custom OS and configuration tools have done superb!
Another good guide for how to install Raspbian OS is at Tom's Hardware.