Well in many ways, properties is a straightforward subject. We all have a rather good grasp of text styles and page layout, things that can be done with fonts, backgrounds, borders and so on. But to really take advantage of the control over appearance that style sheets give us, we need to be able to apply the properties as well.
Selectors are vital prerequisites for mastering style.
Without a good understanding of them, you'll benefit from the added control over appearance that style sheets give you, but you won't be able to take your web pages to the next level. More importantly, you won't be able to take advantage of the powerful site management capabilities of style sheets. So don't just forget about them in your excitement at giving colored backgrounds to headings. But now we come to the fun part, making our sites look more sophisticated. This is no doubt what you've been waiting for.