I first used CreateSpace (CS) in 2012-2013 to self-publish my 6x9 book Episodes:a poetic memoir, about living and overcoming in public my bipolar disease. Of course, no one can overcome it completely, but one can live an almost normal life assuming they take their medications without fail, and there are new drugs out every day. Another key component is having consistent support and love, and my longsuffering wife Janet stuck by me in my worst periods.
What's great about CreateSpace is its Interior Reviewer Tool, where you upload your MS-Word or PDF manuscript (use PDF - it's faster), and see it exactly as printed in your sized book. It highlights errors, mostly surrounding margins and resolution questions, easily solved when you know the ins and outs of Microsoft Word. MS-Word is where you should write your manuscript. It's versatile etc and takes practice to understand its features, but once you do the process is straightforward.
Continue to fine tune your MS-Word manuscript until perfect and Interior Reviewer is clean, then ask for a proof copy to be sent to you (cost about $9-10 including shipping). ALWAYS GET A HARD COPY PROOF and review it carefully for text and formatting errors once you receive it.
Now, this presumes you have a cover. CS has grown over the years and now has Cover Creator to make your own. This is much easier than my first cover where a friend had to take my shadow photograph, integrate it with the background and back cover and spine, and size it all himself. You can now upload your front cover picture or photo, and your back cover Bio picture yourself, and lay it all out, choosing from Cover Creator's format choices. CS does all the proper sizing, including barcode (ISBN) placement, for you - you just follow the layout guides you've chosen.
Or, you can go to a freelancer or media company and pay to have your cover created and sized properly, then upload it to CS. Your choice. I needed to keep costs low. On my second book of 100 short essays titled Solving the World's Titanic Struggles: Answers from Baha'i Philosophy and Spirituality, I did it all myself -- manuscript, editing, CS Interior Reviewer corrections, and CS Cover Creator to produce the front, spine, and back of the book. After receiving two hardcopy proofs, I finished my last manuscript edit in Word, created a PDF, uploaded it to Interior Reviewer, checked every page carefully, fine-tuned my cover, selected all 4 Distribution Channels, and approved the proof online. Four days later the 340-page book was available for $12.99 on Amazon. It looks great and I'm very happy with it.
My daughter-in-law Rachel Richards published her bout with anorexia, called Hungry for Life also on CreateSpace, with artwork help from my son Jesse. It's now sold over 7,000 copies in book form and ebook form and it's only been available six months. With my publishing company, ABLiA Media, I helped a client go thru the whole process, from manuscript editing through CreateSpace publication of The Man Who Never Slept (author Robert Quinn), and all worked beautifully with that too.
CS has its disadvantages. The FAQs and Forum are very sketchy as far as answers to questions, and they don't cover many. But if you can find their phone number for technical assistance, the reps are all very helpful and will solve your issues.