Good study book for 800


Good Chess Books for Beginners and Beyond...
https://www.chess.com/blog/RussBell/good-chess-books-for-beginners-and-beyond
Or just do more puzzles, that’ll get you out 800 in no time.
I got well past 1000 without so much as glancing at the cover of a chess book, and did so quickly.
Just a tip when it comes to puzzles, it’s far more instructive to calculate your solution before you play a move on the board, as opposed to treating puzzles like guessing games where you play the first move that seems promising.
This will help your calculation strength and make you better at evaluating positions, which will consequently lead to fewer blunders.
Good luck out their.

"The Game of Chess" by Siegbert Tarrasch starts with the simplest concepts and works it's way to more complex ideas. Tarrasch was the first to elucidate the basic ideas of positional play and it's his principles that Nimzovich, Reti and other later theorists build on and attempt to undermine. (Be sure to get the algebraic edition.)

"The Woodpecker Method". It's a puzzle book but if you follow the author's directions to doing the puzzles, I guarantee you you will improve your rating. I reached 1400 in blitz and tanked to low 1300s. I did one week of Woodpecker Method and I reached 1500

No books, puzzles.
Get puzzles from a book. Online puzzles are too computerized and you will get more from human approved puzzles. Check out "Woodpecker Method"

Hi! My name is Lauren Goodkind and I’m a respected chess coach and chess YouTuber based in California:
https://www.youtube.com/channel/UCP5SPSG_sWSYPjqJYMNwL_Q
-I recommend two books for you: “50 Poison Pieces” and “Queen For A Day: The Girl’s Guide To Chess Mastery.” Both books are available on Amazon.com. Both books are endorsed by chess masters!

"Bobby Fischer Teaches Chess" - Fischer
For anyone that wants the book for free, check archive.org here