Better tactics book for player stuck around 470 rating

Books are a good Idea, also look at the lessons on chess.com, they are pretty good for all levels. Play longer games 15min or more, it stops you reacting due time pressure, and lets you play more accurate chess.

At your level you should definitely start with Bobby Fischer Teaches Chess. As for choosing one of the two you asked about, although both books are good, I would recommend first working through Winning Chess, and only then follow with Winning Chess Tactics by Seirawan if you are interested in additional instruction in tactics.
For more recommended books on tactics, see...
Good Chess Books for Beginners and Beyond...
https://www.chess.com/blog/RussBell/good-chess-books-for-beginners-and-beyond
Discovering Chess Openings...Attacking The King...Simple Attacking Plans...The Winning Way...
These are all superb books,that can be understood "relatively early" in one's chess education....but...At your level...definitely "The Complete idiot's Guide To Chess"!
The name is a bit silly,but it is a fantastic book for beginners and a load of fun to read.You'll learn a lot about the game and it's history as well.......I loved it!
Good luck