How to install Linux on a Mac using a USB stick?

So I wanted to install linux on a mac mini that I have. They are great because they take up so little room and you can stick them so easily. The tricky part is how to make a usb stick that the mac mini will boot of. As you can see these commands are carried out on my mac laptop. Make sure you do not dd your internal hard drive. Once these steps are completed you should be able to boot off the usb stick and complete the Linux instillation.

laptop:Downloads user$ hdiutil convert -format UDRW -o target.img CentOS-7-x86_64-Minimal-1511.iso
Reading Master Boot Record (MBR : 0)…
Reading CentOS 7 x86_64                  (Apple_ISO : 1)…
Reading  (Type EF : 2)…
.
Reading CentOS 7 x86_64                  (Apple_ISO : 3)…
.................................................................................................................................................
Elapsed Time:  8.612s
Speed: 70.0Mbytes/sec
Savings: 0.0%
created: /Users/user/Downloads/target.img.dmg
laptop:Downloads user$ diskutil list
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *121.3 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:          Apple_CoreStorage ;)                      120.5 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
/dev/disk1 (internal, virtual):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                 Apple_HFSX ;)                     +120.1 GB   disk1
                                 Logical Volume on disk0s2
                                 BB443DB6-4F8C-420F-BE48-911D731081F9
                                 Unlocked Encrypted
/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *2.0 GB     disk2
   1:       Microsoft Basic Data Untitled                2.0 GB     disk2s1
/dev/disk3 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        +29.2 MB    disk3
   1:                  Apple_HFS UNetbootin              29.1 MB    disk3s1
laptop:Downloads user$ diskutil unmountDisk /dev/disk2
Unmount of all volumes on disk2 was successful
laptop:Downloads user$ time sudo dd if=target.img.dmg of=/dev/disk2 bs=1m
Password:
602+1 records in
602+1 records out
632262656 bytes transferred in 235.989425 secs (2679199 bytes/sec)

real	3m58.249s
user	0m0.013s
sys	0m8.404s