Yes. I agree that amazon is great. Also check out the website Adafruit. They deal with many different projects regarding the raspberry pi. The Pi 3 just released.
For burning the SD cards, I use Apple Pi-Baker.
Using DD can be dangerous to any of your Mac's HD, especially if you mistake the of= part. From my QNX days, dd (disk dupe) is a great utility, but it can and will overwrite your HD, and not say "sorry". I'm not sure about whether there's an "are your sure?" in the Mac version, as I don't want to find out, and spend a day restoring my Mac.
Love the "back story" on these commands! For 46 year old operating systems (*NIX), we need to remember where these came from!The name "dd" is actually a really obscure joke and was, I think not intended for duplicating disks, that use came later. The joke makes sense only to people as old as me who can still remember the old IBM mainframe operating system called OS/360. In support of dd not being used at first for disks lok at the two parameters "if=" and "of=" these are input and output FILES. The dd command's purpose was to copy bytes between files while doing some kind of transformation on the bytes and/or block sizing (as on tape) The commands purpose was to translate data from other computers like the IBM360. Then some smart guy figured it would work for making copies of disks or parts of disks and other uses.
Love the "back story" on these commands! For 46 year old operating systems (*NIX), we need to remember where these came from!