new website that surely deserves a visit. I recently discovered many helpful resources there that I had not known about before.
Romanitas sells server cards, ceremonial books and notes, and classic reprints (e.g., Edwin Ryan's Candles in the Roman Rite, Geoffrey Webb's The Liturgical Altar, and various books in Latin by Callewaert). The "Peregrinus Gasolinus" stories from the 1930s, humorous fictions about points of liturgical ceremony, are definitely worth a look. His lists of rubrical reading materials and "where can I find...?" are excellent. Louis also offers training and consulting services.
Of note is a recently added set of articles about the altar bell (part 1, part 2).