Mary,
I think the Romatic Rose Garden would be a perfect Chatelaine for you to start with. It is not as large as the regular size Mandala's but still has the feel and of course those delicious silks. The chart is preprinted and easy to work with. I have this one ready to go in my stash as well.

I was also introduced to silks via Shepherds bush, and I had no idea they were silk. I just loved the texture of the thread and the "tenderness" for lack of better words of the designs. I have a full wall of them completed, and to this day, everytime I pass by I just drool. I'm not sure if it is because of the silk or just because of the design themselves or a combination, but I have not grown tired of these little beauties. They still have a spot on my wall.

When I found Chatelaine it was by purchasing a chart through a LNS called knotgarden. I loved the colors, but again, had little experience with silk threads or delica beads. I started this one, then saw a yuku website listed on the chart, it has been all downhill on the addiction route ever since. I liked the colors of the Mystery (Carribean), fumbled my way through the downloading of PDF, learned to enlarge these beauties, and I'll never turn back.

I have found that Martina uses a lot of the same silks on her designs, so my already accumulated stash is useful and never wasted. There are some silks that are easier to work with than others, but they are all glorious none the less. Sometimes when I get to the DMC sections, the feel in your hands is very different and the tension on the thread is different. I still love my DMC, but ohhhhhh those silks. I liked them so much that I am doing Christmas at Hawk Run Hollow on Vicki Clayton Silks, and you know, they are very economical and of great quality with a lot less expense. I probably wouldn't use them for a Chatelaine simply because the colors sometimes aren't 100% close to the original but most of them are really close. I've also heard that Eterna silks were good, but have never used them myself. Because the Christmas at Hawk Run hollow is a sampler, I didn't go back and look at the color comparison, but I did purchase the VC Silks for Sabrina, I haven't started it yet, but I'm thinking they will look fantastic as well.

WIP's:  Chatelaine Designs (KnotGarden, Fairy Flower Garden, Rahjasthan Lotus Garden, Queen's Farmhouse), Shepherds Bush (Sophie's Roses), TGOSM (Mermaid Jewell Case), Miribilias (StarGazer, Sabrina), Carriage House (Christmas at Hawk Run Hollow), HAED (Mermaid)
Waiting in the wings:  Baroque, Venice Mandala, Sophie's Stocking