Reddit reviews Random House Guide to Cryptic Crosswords (Other)

I learned from this book. New copies go for ridiculous prices, but it seems that you can buy used copies that aren't all that used. The book is stellar; the authors remain my favorite setters.

American cryptics are typically more "logical" and adherent to the "rules" in their cluing, and therefore easier. Many British cryptics take a lot of liberties, which, yeah, make them really difficult if you're not used to them. (I mostly can't do them.) Their colloquialisms don't help, either.

I started a blog a few years ago that aimed to teach cryptic solving (and helped me practice setting!), but I fell off the wagon a few posts in. Maybe I'll pick it up again.