Trying to "randomly learn" Photoshop CS won't even scratch the surface. Some of the tools and actions are not exactly intuitive in the way they work, especially as opposed to the names. What I mean is you can't necessarily tell what a tool does by it's name, and if you can figure out what it does, figuring out how to effectively use it is entirely another matter. For instance, the "unsharp mask". Not knowing what they do and trying to use them the way it "seems" they should be used will net you unpredictable and unexpected results at best.
It is possibly one of the most complex and flexible pieces of software on the planet. There are college courses to teach how to use it. The basic tutorials have more than 20 hours of instuction just to teach the very basics. Trying to learn from scratch on your own with no previous Photoshop experience is an exercise in futility and will very likely result in frustration and just giving up on it.
At the very least buy some books, such as those by Deke McClelland, Scott Kelby or Dave Cross. Buy some of the tutorials that include a book and CD, or one of the CD based tutorials by Deke McClelland. If at all possible, take some courses at your local University. There are some good ones under the Continuing Education programs.
You might consider joining NAPP. They offer some pretty good instructional opportunities also.