Welcome to the Apple community and congratulations on your new Mac.
Ok, I would consider a protective case/cover for it see amazon.com, or retailers near you to see what may meet your needs.
You should consider external storage for regular backups and a bootable clone. See https://discussions.apple.com/message/18893335#18893335 for information about backing up with a mac.
You may want an external monitor/keyboard/mouse. You should visit your country's apple store/website for details.
You may also want a carrying case/bag for when you're on the go. I suggest you visit a retailer in person with your mac and test out the options they have so you can see what you like best.
For programs consider the "iwork" suite of applications as apple's equivalent of "office". Microsoft does offer a version of office for mac.
Apple has a basic "switch" guide located http://www.apple.com/support/switch101/
There are also other resources for "mac os x for windows users" Search on your favorite search engine for more information.
I hope this is helpful and again, welcome!
Welcome aboard! uselessSABATOGE offers some very good suggestions. I highly recommend reading the "switch" document that he refers to and remember that should you have any questions, regardless of how basic they may seem to you, this forum is always here for you.
Since you just got your new MacBook Pro Retina display, you will be eligible to upgrade to the new version of OS X, Mountain Lion, which will be released in the next couple of weeks. If I were you I would wait until the new version of the operating system is released and then buy the "Missing Manual" book which is sure to be released soon after the new OS. The "Lion" version was written by David Pogue, a man with a very welcoming writing style, and I'm assuming that he will be authoring the "Mountain Lion" editon. Be on the lookout for the book.
Again, welcome to the Macintosh community - you've purchased a terrific machine and we're all here to help one another out to get the most from our computers.
Thanks for your and uselessSABOTAGE answers. I'm that rapt in the pro retina that I will be buying a 27" iMac.
Should I go for SSD, 16gb ram and whatever else you think that I need. Also, do you think that I would benefit by waiting for the iMac with retina screen.
I WILL NOT BE USING IT FOR GAMES.
I now have the latest 64gb ipad, 64gb iPhone 5 and Macbook pro retina.
I can't believe that I have been using a PC all these years and not trying the MACS.
Once again, thanks for the encouragement.