@rapid: @the_hiro_abides: @soulcake: Thanks for the suggestions re: the Warframe wikia. I'm still early enough in that I'm not concerned about gathering resources yet (though I imagine it doesn't hurt to get started early) and I'm just poking my nose into the mechanics to see what's out there. Hopefully all this "testing the waters" business doesn't come off as Babytown Frolics for veterans like yourselves.
I'm still not sure what my investment level will be but I do want to get to the point where I'm exploring other planets with other warframes at least. It sounds like making new warframes will take some work so I'll keep all this in mind. Maybe I'll make a beeline for the more interesting playable characters, especially if any involve firing actual lines of bees.