I've never been a fan of "Teach Yourself in 24 hours" as you really can't learn anything in 24 hours. You might get an idea of how things work, but you won't truly understand them. That takes a bit more than 24 hours of work. I think I read the Learning SQL book through the course of a week or two and never did any of the examples but learned a lot.
Whatever book you choose, make sure it teaches you the SQL standard basics and not the MySQL or Postgre or MS or Oracle only extensions to the SQL language. Otherwise, you're pigeonholing yourself to use that one RDBMS instead of being able to write portable code.
NOTE: Learning SQL does go over the SQL Standard and has a section about the MySQL Extensions. Also, any derivations by Oracle, MSSQL, Postgre or MySQL are noted about in the text.