The Encyclopedia of Needlework, by Thérèse de Dillmont, provides an excellent introduction to the methods and history of tapestry stitching. The book explains clearly what materials are most suitable for the project and uses plain language and simple diagrams to help the reader understand the different stitches used for tapestry work.
Tapestry is one of the oldest forms of needlework, and it remains very popular. Dillmont explains there are two kinds of canvas appropriate for tapestry, plain and Penelope. She recommends Penelope canvas because it's easier to count stitches on. Traditionally, wool and silk were the favorite materials for tapestry, with wool being preferred for pieces that were meant to be used constantly, such as rugs. Today many tapestry artists work with cotton because it's more durable than silk but just as bright and easier to clean than wool. Tapestry embroidery can be done in a frame or by hand, but Dillmont recommends weighting down a piece that's being worked by hand to prevent the fabric from puckering.
One of the goals of tapestry is to make sure the stitches completely hide the canvas underneath. Dillmont explains many of the popular stitches used to achieve this effect, including cross stitch, gobelin stitch and chain stitch.