The best way to learn Photoshop is to push the boundaries of your knowledge. If you don't know the basic tools then it can be difficult to get started. But true learning occurs with practical real-world application of skills by creating unique projects from scratch.
Parallax web design has become a technique for designing single-page interfaces with extra pizzaz. Many of these animated parallax effects are stunning and fit perfectly into a typical portfolio or landing page design.
One of the newer trends in parallax design is horizontal scrolling. This has been around for years dating back to flash websites but has since made a resurgence. Now it seems that horizontal scrolling is concomitant with parallax animation, meant solely to create a more distinct user experience.
If you're designing a custom parallax layout be sure to check out some of the following examples. Each design uses horizontal parallax scrolling in a unique way to both enhance the design and improve content consumption.