If I buy a Kindle Paperwhite do I have to get books from Amazon?
Kindle devices allow you to load non-Amazon files onto them; you can copy them directly to your device using a micro-USB cable, or have them sent to your device wirelessly, through Amazon's Kindle Personal Documents service.
You are limited to the types of files supported on the Kindle: at present, these are
.azw, .azw1, .txt, .mobi, and .prc.In addition, Kindle can read
It is extremely easy to convert files into Kindle-supported formats from other popular formats -- such as
.epubfiles, Word documents, and web pages. Amazon's Personal Documents Service can help you with transfer and conversion, and Calibre is an extremely popular tool for ebook-management which provides such conversions easily. PDF files which are mostly text are also quite easy to convert to a supported ebook format.
The one big wrinkle in the all-around compatibility I'm describing here is that books protected by DRM (a Digital Rights Management scheme), the DRM prevents it from being converted into different formats. So an ebook you buy at barnesandnoble.com, which is formatted and protected exclusively for the B&N Nook e-reader, cannot be easily converted for the Kindle.
Many major ebook retailers rely on DRM to help "lock you in" to their specific device, platform, and store. So basically, ebooks you get at non-Amazon stores are unlikely to be compatible with the Kindle (unless they specifically note that the ebook has no DRM), whereas ebooks from other sources (e.g. the out-of-copyright classics at Project Gutenberg, or ebooks you create yourself using a service like Instapaper) should present no difficulty.
I think this should start "Some Kindle devices, like the paperwhite" According to this the kindlefire is not so friendly.
@JamesJenkins: Hmmm. Never used the Fire myself, but e.g. this article suggests sideloading to be as straightforward as I'm familiar with from my e-ink Kindles.
Posted http://ebooks.stackexchange.com/questions/274/is-it-more-difficult-to-sideload-books-on-to-a-kindle-fire-than-other-devices lets see if we can get more information from someone with a Fire.
I upvoted this answer but suggest you add a sentence about Kindle conversion services - most importantly the ability to convert PDFs to native Kindle format just by sending an e-mail with the attached PDF. It works poorly for PDFs with lots of graphics or multi column but works well for PDFs that are close to pure text.
@JoeGolton: Glad you liked :) I didn't want to get into the deep pool of conversion options in an intro answer like this; Calibre's a good starting point, and the important thing is to know most DRM-less filetypes are pretty interchangeable. Ultimately, you just Google "convert [type] into [type]", and find what you need.
In my personal experience, I email a converted PDF to my Kindle once every month or two - and that pretty much accounts for all (to Kindle) conversions. If I have an ePub I'll just read it on my iPad or iPod touch. More importantly - if the person reading this is not particularly technically inclined, I suspect they will not bother with Calibre, which involves more steps and complication than simply emailing to your Amazon Kindle address.
@Standback, Hmm, if we don't have a Kindle in the first place, are we still able to buy and read ebooks from Amazon ?