Also make wireframes before you code, when something is complicated -- or when you're starting out, for virtually any UI. Use Omnigraffle Pro, and you can also use Graffletopia's website to find stencils, e.g. Bootstrap Stencils. Or use Easel.io.
Also, the Dont Make Me Think book should've really been a two-pager pamphlet, it is really thin on a material. While the center idea is fundamental, it is very easy to explain and to understand.
If we are talking about 10000 ft perspective of the design and its fundamentals, I would raise you The Design of Everyday Things. This is a very good beginners book and it's also an interesting read for those who already know a thing or two.
I would start by using grid based layouts and study those who have used them. Start with wikipedia article on the
Design is more the arena of people like Dieter Rams. You can't design an application, a chair, or a home with sparklines.