The first "chapter" at http://effortlessnow.com says:
"At the core of all suffering lies resistance to the present moment. By lowering our resistance we free ourselves from suffering."
In just a few words, this lays out everything you really need to know in terms of this practice. The first sentence explains the cause of suffering, and the second explains how to dissolve it. This is great, but language is a very unwieldy tool to explain these things, and is fraught with danger, as many words have many meanings. Either the dictionary lists multiple definitions for a word, or the reader interprets a word with his or her own set of predispositions and assumptions. Usually both.
At any rate, do not give up if upon reading the first chapter, your mental response went something like, "That doesn't make any sense," or even better, "That's the stupidest thing I've ever heard." These chapters are crafted intentionally so that upon reading each of them, hopefully at least one thing will jump out as being ridiculous. That's good news, as the less these chapters make sense to you, the more potential they have to really transform your life.
To clarify what the first chapter is describing, we need to define the terms as they are used in this context. The first roadblock we hit is the word "suffering". This practice is all about alleviating suffering, and nothing else. It's not a self-help course to teach you how to be more assertive, or to become more "spiritual", or to even change anything about the circumstances of your life. It is only concerned with removing suffering.
A natural response is, "That's absurd. Terrible things happen all the time. People die. You stub your toe. Suffering is just a part of life, and if you got rid of that, you wouldn't be human anymore." This is where we need to be very clear about what we're talking about when we say "suffering". Specifically, we need to make sure we understand that there is a difference between pain and suffering. In some contexts, these are used interchangeably, but for this practice, we need to keep the distinction. When we say "suffering is just a part of life", what we really mean is that pain is a part of life. There is no way to avoid it, as the response above wisely pointed out. If you are reading this to learn how to avoid pain, you are in bad shape, because it's simply not possible. People will die. You will experience grief, sorrow, and physical discomforts both vague and acute, no matter what practice you study, no matter what path you follow, what defenses you build, what drugs you take, etc.
Suffering, however, is completely different, and if you look carefully at your own life, the distinction is obvious. What suffering really is, is a mental struggle with the immediacy of your experience. In the example of stubbing your toe, pain is the immediate (albeit unpleasant) experience. But then upon stubbing your toe, if your mind begins "arguing" with the pain ("that damn wall", "what an idiot, I need to pay more attention", "is anything going to go right for me today?"), then welcome to suffering. And if you look even more closely, you can see that the suffering -- the secondary, mental reaction to the experience -- is usually far, far worse than the original pain that came before.
Pain happens, it comes, then it goes, and even though it's painful, there's a lightness to it, as a natural experience. It's in the suffering where it gets heavy, where it gets deadly serious, where it begins to destroy our lives.
So that's what this is about, dissolving the suffering. And when that happens, pain is no problem at all.