I discovered the SIX STRINGS PUBLISHING website when I googled chord synonyms.
This site is a gem.
There is a large amount of information available for the beginner or even the advanced player on this site, which has quite extensive excerpts from their books.

There is a playing tips tab. Topics covered include solos, (pentatonic and blues scales), sounds, guitar amintenance, theory, and accompaniment.

Not all the lesson material is under the tips tab. You click on an advertised book and along with the spiel there are usually links to excerpted lessons. After studying the material you will presumably be impressed enough to add the publication to your shopping cart.

The lesson material on synonyms and chord substitutions is found by drilling down on the home page tab for guitar chords and accompaniment to the book "more Jazz Guitar Chords and Accompaniment".
http://www.sixstringsmusicpub.com/index.html