Use this video, by legendary Halo speed-runner RC Master, to use tactics on how to survive The Library without a single death.
http://www.youtube.com/watch?feature=iv&annotation_id=an...However, I strongly recommend doing Speed Reader and That Just Happened separate. That Just Happened......is easier than you think. Much easier than Speed Reader. I got it in one run, without having to use the checkpoint glitch (See darkwatchman's post at the top of the page). Just take it slow, never run-n'-gun it, make sure to have Bandanna, and practice those 'nade jumps! (Remember: Jump right as the grenade goes off, and crouch right at the ledge your trying to get to).