It has been some years (before 2009?) since I've read this book. The story starts off with this boy [teens] who can sleep anywhere, even with his eyes open, and can do this on cue! This secret company find him and tells him about this place with other kids. They tell him he has been selected for this group that protects the timelines or something. I not sure how but they do this through stripping off all their clothes and going to sleep. When they wake in "dream" they have proper clothes on for that time period, and have something they are looking for that doesn't belong or something.
He goes on this journey with two friends he makes. This girl who at some point gets her hair braided by these tribal women with amazing hair. In the end they strip again and fly to this secret place they been trying to find which is the root of this disturbance in time or something. I seem to recall this real meta guy comes and takes him to the beginning of time and they end up taking this whole civilization there to save them all and save time.
In the end he wake up and meets the head guy and I forget everything else but that's where it ends.
This story is part of a series of some kind and this was the 1st book. From my memory it was real big (over 500 pages) and had this snake on the cover in a circle of sorts (that's what caught my eye to pick it up) and I swear it had Dream in the name 1st. I don't remember it having any awards but I thought it was really good.