Thanks for the replies everyone, you've answered a question or two... which leads to more questions (naturally!).
From Jon:
...when considering which color space to use in their workflow is, "Why do I want to use this colorspace?"... Is it because it the latest and greatest and I just want to stay current?...
For now almost all of my workflow output will be for the web, although I do want people (myself included) to have the option to print down the road as the mood strikes. Prints would likely come from a lab and would not be done by myself or any friends/family/clients themselves (speaks to sRGB). That will likely change in time to wanting to print myself, but not anytime soon, I have a lot more learning to do.
As for why I was wanting to (consider) using Adobe in-camera, quite frankly I saw it there on the camera and thought "I'm using Adobe software in my workflow, so should I be using this color space when shooting RAW?" and then came across this thread.
From Victoria:
In reality, it won't make a huge difference, but you'll notice the reds may appear blown earlier when set to sRGB than AdobeRGB, so you'll get the most helpful histogram from the largest colour space available.
That makes sense to me, thanks Victoria. It would seem I'm better off shooting in Adobe in-camera instead of sRGB (remembering that I'll have to convert back to sRGB on export rather than rely on profiles) to get a better idea of exposure in the field.
That said, given most of my work will be for the web and will therefore be exported as sRGB, I'm wondering if I'm maybe better off leaving my camera set to sRGB to evaluate exposure?
I realize that the histogram on the camera will have little bearing on what the final output will be after I edit the RAW files -- I guessing what I may be missing is the connection between what I see in LR (and/or PS) histograms and what I may be clipping once exported under sRGB (jpeg), apologies if my questions (logic?) have/has some holes. I also realize that histograms aren't the be-all-end-all and that there's quite a few other technical factors to consider, not to mention personal taste and/or subjective factors as well.
I'm afraid I know just enough at this point to ask some pertinent questions, but don't know enough to keep myself from making some basic mistakes.
I start a 6 week night course on PS next week -- while it's not a LR course (there aren't any in my area), I'm also using PS and I'm hoping I'll learn a few of the broader concepts that will let me understand not only LR and PS and how they are related, but also post processing and more about photography in general as well.
Back to Jon:
You also want to know what bit depth you want to work in even before you determine what color space you work in.
Yes, I'm vaguely aware of bit depth, but don't know enough to speak to it, yet (maybe later tonight!

). I'm doing my best to research all of this in a methodical manner, but at some point I decided I better just jump in and start mucking about a bit with real examples. With more 'net research, a course, some books and practical examples and experience, I'll get there, and then (try to) help others.
From Denis:
Very legitimate question everyone should ask themselves.
And HERE are some enlightnening answers that may help.
I understood some of that Denis, thanks for the link.
Something that is concerning me now is remembering to think about how to achieve the best possible shot when I'm actually taking the photo, instead of thinking about how I'll adjust it after the fact. I think there's a balance between the two that we're all continually striving for, but for now I appear to be focusing on learning more about this new computer, new software, and how they figure into my workflow, given that I've recently decided it's a good thing to be working in RAW.
Cheers, Sean