Puzzle library
Everything there is to solve here, grouped by subject: 9,159 cryptograms across 56 collections. Each subject links through to the collections behind it.
Literature
Quotations taken from the books themselves — Victorian and Edwardian novels, each collection one book with a pinned edition, graded easy to hard.
8,859 cryptograms in 50 collections.
Science
Sentences written for this site, each one a fact with the source it came from and the date somebody last checked it.
300 cryptograms in 6 collections.
Other ways in
The quotations are also listed by author, and every puzzle is graded on what its own letters give away rather than on how long it is: there is a page on each grade, written from the catalog itself. If these are new to you, start with how to solve a cryptogram.