When you obtain the ISBN for your book from CreateSpace, the ISBN shows up in your dashboard. You should put that ISBN on the copyright page (title page verso) of your print book. First, you’ll need to add hyphens. CreateSpace puts a hyphen only after the 978, but there should actually be four hyphens. According . . .
People complain that InDesign won’t export decent EPUBs. I have to disagree. You can get pretty decent results from InDesign if you optimize the file for EPUB before exporting. Here are the steps that I follow for InDesign CS6. Make sure styles are applied to anything that needs to be different from the base font . . .
Do you plan to use a pen name aka pseudonym aka nom de plume? If your pen name will be an open secret and your main purpose in using one is to differentiate between the various genres you write in, go ahead and register a DBA (fictitious business name) for your pseudonym. Having a DBA . . .