Short Version
1. Before inserting the USB, check which disks you already have.
2. Create a new directory under /mnt to which you will mount your USB.
3. Now insert the USB and mount it.
4. Now you are ready to read and write to your USB.
5. To unmount.
Longer Version
In Linux a storage device is represented by a device file in /dev/.
The three letter naming convention for storage devices in Linux are:
- s - storage
- d - disc (such as SCSI, USB, SATA), cd - cd or dvd
- litteral order character, starting with a, then b, c, etc
Example: /dev/sda (SCSI, USB, SATA), /dev/sdb (SCSI, USB, SATA), /dev/scd (CD/DVD)
These device files represent the whole drive. Each drive is partitioned into partition. The first partition receives order number one, the next one two, etc
When a new storage device is added it will receive the last character order literal, here it is b (/dev/sdb). Another way to find out the device file is to tail the dmesg log file.
Here we see that the USB was allocated device name sdb. But when you mount you mount to a partition that contains a file system. And in general, most USB only have one partition, hence sdb1.