Wow--congratulations on your accomplishment so far. Was that a NaNoWriMo effort, or an ongoing project?
You ask some great questions, all of which I hope to answer in detail as I build out the articles on my site, but I'll try to hit you with some quick answers right here.
If you have an active following already, then you've got the hard part--marketing and sales--licked. The reading software, purchase transaction, and delivery are all handled by Amazon, B&N, Smashwords, etc., as I mentioned in the article. As far as the links, yes, you just link to the sales page on their site, just like with any other book, for example, here is my Amazon book page for
Little Miss Straight Lace .
If you sell through these retailers, people can read your book on pretty much any electronic device with a screen, such as a PC, a smartphone, or a dedicated reader like the Kindle or the Nook. There is free software available that handles the different file types on these different devices, so pretty much anyone can read anything anywhere, as long as it's not DRM'd (digital rights management protected). I get into this topic a bit more in this article,
Ebook File Formats (apparently, a very popular topic, as it's had almost 900 reads since I wrote it last week!).
The different retailers have different ways of handling the files, but for the most part, yes, you can produce a file, such as in the epub format, which is portable across systems & devices. If you'd like to see some samples of the different sofware and ebooks, just go on any of those three sites and "buy" one of the many free ebooks they offer, download the PC version of the software, and try it on your machine.
Well, I should say, Smashwords doesn't offer their own reading sofware, but they offer all books in mulitple formats, including HTML and PDF, so that would work for anyone.
Good luck and let me know if you have more questions!
--Maria