It is to provide links to free public domain or creative commons licensed materials which can be used commercially to publish a book, or programs which are stated by their sources to be used for such as well. I use most of these sources myself in my book creation process.
On everything listed, to the best of my knowledge and research the information is correct, but it is your duty to check this out for yourself.
Custom book covers I can do as a sideline, and some are available on my personal blog >My Blog Here<. (Should open in another window.) However, I seriously advise you learn to do this yourself as well as I provide links to the necessary programs. If you find one irresistible though, I will not complain. ;)