My wife's an amateur singer and I'd figure a nice USB microphone will allow her to play around with Garage Band and record with ease. I know USB microphones aren't ideal for various reasons, but we're just playing and I don't want to get involved with tons of gear.
Suggestions? Seems like a lot of the recommended microphones (like blue) are meant more for narration than singing - I'd like a flattering sound signature over analytical.
I have a lot of experience here from acoustic recording
The problem with USB mics is unless you have a really decent computer, you may get some recording lag. If you're laying tracks, the lag makes it difficult to get everything lined up. For voice, you'll probably want a condenser mic to get an accurate recording.
That said, how much are you looking to spend? In the $100 or less range, Samson makes a decent line of low cost mics. Behringer is also a decent brand in that price range.
In the $100-$300 range, you can look at brands like Shure, Audio-Technica, and Apogee (MXL is also in this range, but I've had quality issues with their products).
You'll also want a stand and a pop-screen.
Honestly though, you may want to look at something like a TASCAM multitrack recorder and get a standard mic. It will be under $250, more versatile, and you'll get better results. I never record on a PC. Only use them for mixing.