Welcome MP. You've got an Echeveria hybrid, possibly one of Dick Wright's. Here are some websites with pictures that might help:

http://www.flickr.com/photos/33610540@N07/sets/

http://www.echeveriasinoz.com/feature.html

It is natural for the lower leaves to eventually die and fall off. There is a recent post (http://forums.gardenweb.com/forums/load/cacti/msg0600240429885.html?7) where I have added some pictures showing what you do once the head grows too tall and the plant becomes top heavy.

Next, while hard to see, your soil mix looks a bit on the heavy side and this could spell root rot at some point in time and why you're dropping so many leaves. You may want to repot in something containing more grit such as perlite. Then again, if your soil is dry and the leaves soft, might require more water. It all depends on your weather conditions, the air circulation and the plant location. This Echeveria wants lots of sun to maintain its color.

The leave you are holding will probably not root and grow another plant because it is yellowing and dying. If you want to do leaf production, you have to have a good healthy leaf. Not all hybrids will grow from leaves.

The gray colored Echeveria in the side pouch, under your finger, is E. runyonii 'Topsy Turvy'. Can't make out the others.

I had the same problem with mine, and noticed that at the nursery, these plants tend to have less than perfect leaves. Eventually, mine flowered, and then after that, "pups" formed on the lower part of the stem, so the plant lives one. The best label I could find was ruffled echeveria.

I love the potting arrangement. Very creative. The blue green succulent to the lower left of E. runyonii looks like Senecio vitalis or "Blue Chalk Sticks" and the one above the Senecio looks like a pachyphytum, potentially oviferum or "moon stones" although I could be mistaken.

The one I circled in red in your photo looks to me like Baby toes - Fenestraria aurantiaca. Not sure thou, could you take close-up?
Rina

Ah! You guys are so awesome. Thank you so, so much!

@bikerdoc5968 I've potted everything with the cactus, palm, and citrus soil by Miracle Grow. The planter pictured above is outside. It gets morning sun, but I'm from West Texas so it seems to dry out relatively quickly - the top five inches or so anyway. I just planted a few new things and tried soil mixed with perilite. They seem to be showing new growth quicker!

@dorianscale3 yay thank you! I just googled to compare pictures and you're right on both plants. While the no label thing is kind of frustrating, it's also fun as I slowly figure out what I've got in my collection, haha.

@rina_ just compared pictures! Definitely baby toes! So cute. That plant was in terrible shape when I brought it home, but it's bouncing back now. I'm continually amazed by succulents ability to withstand.