What's the best way to get text into the header?
For example, from left to right: logo, block of text, another block of text.
See http://healthsummitchiro.trentstudios.com/

I've tried creating 3 divs and align aligning them, and putting all of those into a container with a width of 990px ( same the container for the site ), but then the navigation appears on the right of everything.

WP 3.3.2
Atahualpa 3.7.5

One way is to use the New Widget Area function and add a three celled widget area in the top. Read through the instructions with regard to the code for the alignment of the content. Then add three widgets with the logo, the text, and the other text. Instead of image or text widgets I typically use this plugin to create text blocks that can be inserted into widget areas.