I've searched everywhere in books and online and I'm still having a difficult time identifying this plant. It's very young so I'm not sure the leaves are exactly what they'll look like when they've matured, but I'd like to take appropriate care of it by identifying it.
The first picture looks like a relative of the Aluminum Plant, look up 'Pilea', but the other pictures look like the leaf is thicker, and maybe a Plectranthus, one of the plants called Creeping Charlie or Swedish Ivy.
Thank you all very much! I realize it can be hard to determine exactly the type of plant one is just by looking at a few out-of-focus pictures. :) After researching your suggestions and comparing the plant with them, I now believe it to be the Pilea nummulariifolia.