Check out the Dover Needlework Series. Inexpensive. Fantastic designs. Lotsa historic stuff, with notation as to where the original can be found. Here are two some favorites: Charted peasant Designs from Saxon Transylvania. ISBN 0-486-23425-8 Charted Folk Designs for Cross-Stitch Embroidery. ISBN 0-486-23191-7
Two magazines, one in print and one not: Burda Sticken nach Volkskunstmustern. If you see this anywhere in a bookshop, grab it. And then mail it to me. Sampler and Antique Needlework Quarterly. Excellent reproduction charts and decent articles if you want to know about embroidery supplies. This is probably the only thing on this list still in print.