AE Facebook noted the After Help resource pages on Time-stretching and time-remapping; see also the Help pages on Timewarp and other Time effects. Andrew Kramer's 29. Speed Variation pretty much covers it in video.
You can also find a few extras from some old reliables: Freeze Frame with Time Remapping, a video by Aharon Rabinowitz; Animate Time, a PDF by Mark Christiansen; and Change of Pace, a PDF by Chris & Trish Meyer.
There's not much new except a few techniques (one using RE:Vision Twixtor plug-in) mentioned in recent posts Motion estimated morphing time-remapping on stills and Adding motion blur to video or 3D renders, and a slight tangent with Keying, Time Remapping, & Stills in Premiere CS5.