Stitch guides are available for some Patt and Lee canvases. Patt and Lee canvases are unique in that they are available on whatever size canvas you specify, and you can also buy a charted version. This summer (2010) Patt and Lee plan to release their most popular designs as painted canvases. Right now they are solely a printed canvas company.
The link below is to the stitch guide section of their website. They have many more than just these, but they are adding guides to their canvases faster than they can update this page. Browse their site and check the descriptions of anything that catches your eye to see if there is a stitch guide available. No prices are listed, probably because this is a wholesale only site. Some of the stitch guides are by Janet Perry and others are by Patt herself, plus I did a stitch guide for Pirate Cat.
UPDATE: Patt and Lee have the stitch guide ready for their charming Puppy Love canvas. This looks like great fun for a counted thread person who is looking to start painted canvases.