I'm interested in making some simple digital voice recordings for use in educational software, and I'd like to have crisp, full sound, not tinny and full of noise. From the minimal research I've done, it seems that I need a unidirectional microphone, and some sources claim that USB mics have better sound than analog ones.
As for which mic to buy, I've seen recommendations ranging from a $25 headset designed for VOIP applications to professional mics over $600. I figure that for voice only, I can probably get away with something cheaper and some processing with Audacity. In general, I think I should avoid headsets, as I'm thinking that I might like to use the mic for two-person conversations and other things.
How about acoustics? Do I really need to set up a proper recording studio stuffed with acoustic foam, or can I get by with a quiet room and a decent mic?