Any Remade By Hand pattern that involves grafting will give you tips as well as specific instructions for how to work that pattern's particular graft. However, there are some great basic resources out there on grafting in general. Here are a few of my favorites:
Bluprint’s Ins and Outs of Grafting class with Anne Hanson -- This free video-based class covers grafting basic stitches as well as adjusting tension and other great tips.
Knitty.com's grafting tutorial -- This article covers grafting in Stockinette through a series of clear photos and explanations.
Solene Knits's grafting tutorial -- This article covers grafting in pattern.
Romi Hill's grafting tutorial -- This article explains how to use waste yarn to help see where to graft pieces in pattern.