You would be at risk of being liable for copyright infringement, as posting copyrighted works on the Internet can constitute infringement.
You can avoid infringement by obtaining the permission of the party that owns the copyrights to the book. They might grant you permission for free, or, they may condition it upon you paying a license fee.
There is a possibility that the book, or some of the individual poems are in the public domain. It may require some work to determine if this is the case. Public domain works may be posted on the Internet without the risk of infringing a copyright, but you should be sure to correctly identify the author(s) of the poems.
Paul B. Overhauser
Under general principles of copyright law, what you describe would infringe the exclusive right of the copyright owners of each poem, as well as of the editor who chose the particular assortment, to make and distribute copies of a copyrighted work. See 17 U.S.C. section 106(3), which confers the exclusive right on the copyright owner "to distribute copies or phonorecords of the copyrighted work to the public by sale or other transfer of ownership, or by rental, lease, or lending."
Not only does each poet have a copyright in his or her poem (unless a particular poem is so old that it has entered the public domain), the person who made the particular selection of poems in the anthology has a copyright, not in any individual poem, but in the particular assortment he chose. The act of scanning the work would likely constitute at least one hundred and one acts of infringement (100 poets plus editor), and the act of putting the work online would likely constitute another one hundred one acts of infringement. So, Two Hundred Two (202) acts of infringement!
And if the copyright owners, who would be entitled to sue for statutory damages at the usual rate of $750 to $30,000 per infringing act, were to sue, a court could award the copyright owners anywhere from $151,000 at the low end, to $6,060,000 at the high end, for putting the book online.
Short answer: Don't do it!
Not legal advice, just some general information about copyright infringement as applied to the facts you describe. You and I don't have a confidential attorney-client relationship and I don't practice law in Indiana or hold Indiana licensure. If you need legal advice, please consult a lawyer who does.
It depends if anyone of those 100 poems still has copyright rights. If not then you are free to use it anyway you like it. For those poems that are still under copyright, you need a license from the copyright owner, check www.copyright.gov for who is the owner, or you will be infringing and be subject to liability.
The earlier questions are all accurate: You would not have the right to copy a book and then just turn it into an ebook. That would violate the rights of the book author/compiler.
That said, if any copyright in the underlying works has expired, you could create your own book with those. But keep in mind that you might need to do more than just re-order the un-copyrighted poems. It would still be a compilation, just re-ordered.
And the same general advice applies to all books: Generally, no you cannot just buy one copy and turn it into a digital copy.
Google is in the process of scanning and making availing both public domain copyright but out of print books. A class action suit is pending by a class of authors. A settlement was rejected by the trial judge last March. But a trial has ben delayed by the elevation of the trial judge to be an appellate judge in the 2d Circuit.
Information here is general and is not a substitute for consulting with an experienced attorney on the specifics of your situation.