I don't have a lot of experience with all-grain brewing, but one of the best resources out there is John Palmer's "How to Brew" book. He has the first edition for free at www.howtobrew.com
. The definition of a saccharification rest is given at http://www.howtobrew.com/section3/chapter14-5.html
The temperature will depend on the recipe. In your recipe, it looks like you dough in at 154, and probably rest there for 60 mins. After lautering, I would then dump in 168 degree sparge water, let it rest for about 10 minutes, then lauter the rest of the wort. Some people have heatable mash tuns, so they are able to raise the temperature after the 60 minute rest before they lauter the wort.
I've only done one all-grain recipe, so one of the more experienced brewers might chime in with more details.