Hi, mnhutson,
Welcome to the forum and soapmaking!
You've already got lots of good advice here, but I'll throw in my own two cents' worth, too.
I'm a M&P soaper, and I, too, have found Bramble Berry to be a great supplier. Quality bases, fragrance oils, colorants, and other fun stuff. I like that it's pretty much one-stop shopping, and I know I'm getting the good stuff.
The sampler packs are a good idea. You can get samplers of glitter, micas, oxides. I've bought the glitter and mica samples, and plan to get the oxide sampler next time around. The fragrance sampler packs are a good idea, too, if you're doing small batches of each.
As far as the minimum to get started, in my first order, I bought a couple of pounds of clear soap base, a couple of pounds of white, a couple of 1 oz. fragrances that sounded yummy, liquid colorants in red, blue, and yellow, and a couple of basic shapes molds. Also, a couple of 4-cup measuring glasses, a cutting board and a knife or cutter, some mixing spoons, and a set of measuring spoons. Plastic wrap for covering the glass cups while microwaving (so the moisture doesn't evaporate) and some wax paper to protect my work area. Oh, and a spritzer bottle of rubbing alcohol to spritz away bubbles after pouring and to make layers and embeds adhere better. That got me started in the right direction. Soon, I was checking out the baking section of my nearby crafts store and finding fondant cutters (they're like mini cookie cutters) and candy molds to make embeds.
Things I can't live without? A scale of some sort to measure ounces of cut up soap before melting is absolutely necessary for me. And I love my loaf mold and crinkle cutter!
Hope this helps. Have fun soaping!