Forgive me if I'm wrong as I haven't read them, but wouldn't the Harrington books offer a lot of advanced concepts not really applicable to the level the OP is playing? Honestly for those levels I would recommend Phil Gordon's little Green and Blue books.
I agree they might be a bit basic, but they are very solid and with the strategies provided he could definitely beat those levels. Also there is a decent amount about cash in them. So you would recommend Theory and Practice as a good book to follow those?
No one that plays NL should ever read SuperSystem and try to apply its advice to todays game.I still think super system is the bible hold em poker. Whether cash or tournament play you can't go wrong with the best.
Has anyone read this-
Amazon.com: Professional No-Limit Hold 'em: Volume I (9781880685402): Matt Flynn; Sunny Mehta; Ed Miller: Books
It looks good from the description and reviews.
Also very good. As is SSNL (eBook) by the same authors.
That ebook is excellent. And at $100, it's a bargain (compared to those of CTS or belugawhale).
http://smallstakesnolimitholdem.com
EDIT: tbh, that ebook is targeted to somewhat advanced players. its goal is to teach you how to beat 200nl 6max online when you're already able to hold your own at 50nl or something like that.