Posted 15 November 2012 - 04:31 PM
The Missing Manuals will go into more detail that HF HTML & CSS does in that it will include some properties and information we leave out. The goal of HF HTML & CSS is to teach you the core concepts so you can more easily learn the rest yourself. Assuming you have those core concepts down, then a good reference book on HTML and CSS would be good (the pocket guides are nice).
Personally, I think the best way to become proficient once you know the basics is to set yourself some goals to build progressively bigger projects and review / look up what you need to as you go. Look around the web at some web site designs you like and see if you can replicate the design using the CSS and HTML you know already. View source, look at the site's HTML and CSS and use a reference book to help you understand what you don't already know.
Hope this helps!!! Let us know how you progress.
Author: Head First HTML5 Programming, Head First HTML and CSS, Head First Design Patterns