#1 - The copyright term in unpublished works is governed by 17 USC § 303:
(a) Copyright in a work created before January 1, 1978, but not theretofore in the public domain or copyrighted, subsists from January 1, 1978, and endures for the term provided by section 302. In no case, however, shall the term of copyright in such a work expire before December 31, 2002; and, if the work is published on or before December 31, 2002, the term of copyright shall not expire before December 31, 2047.
§ 302 basically sets the term of copyright as life of the creator plus 70 years after death, or else 120 years from creation in the case of an unknown creator.
So, it's fair to say that given your facts, the majority of your photographs are still covered by copyright.
Your right to display these works publicly would be restricted by 17 USC § 106:
Subject to sections 107 through 122, the owner of copyright under this title has the exclusive rights to do and to authorize any of the following:
(5) in the case of literary, musical, dramatic, and choreographic works, pantomimes, and pictorial, graphic, or sculptural works, including the individual images of a motion picture or other audiovisual work, to display the copyrighted work publicly;
So, were you to display those photographs in an art gallery without the permission of the original authors, you could technically be liable for copyright infringement.
While you could not publicly show the photos, you could possibly sell them, under the terms of 17 USC § 109:
(a) Notwithstanding the provisions of section 106 (3), the owner of a particular copy or phonorecord lawfully made under this title, or any person authorized by such owner, is entitled, without the authority of the copyright owner, to sell or otherwise dispose of the possession of that copy or phonorecord.
So, assuming these copies are under your lawful ownership, you could sell them.
#2 - The paragraphs describing the photos would probably be considered fair use. On the other hand, the actual reproduction of the photos would most likely not be considered fair use under the factors in 17 USC § 107:
including such use by reproduction in copies or phonorecords or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use the factors to be considered shall include—
(1) the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;
(2) the nature of the copyrighted work;
(3) the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and
(4) the effect of the use upon the potential market for or value of the copyrighted work.
The fact that a work is unpublished shall not itself bar a finding of fair use if such finding is made upon consideration of all the above factors.
So, while the non-commercial nature of your use (assuming you're not either selling the guides or using them to promote your commercial interests) could possibly tilt (1) in your favor, you'd still be contending with a situation where the majority of the factors would be substantially against your use, in my opinion. The works are unpublished, and possibly were never intended by their authors to be made especially public, you'd be copying the entire photos, and your book could potentially displace a pretty large part of the market value for a previously-unpublished photo, especially if the subject is especially rare.
Under a traditional copyright law analysis, it seems like you'd be infringing on copyright to do what you propose.