The professional quality USB microphone is the easiest way to go ahead
. Several companies have versions of their standard USB microphones. They connect directly to your computer's USB port, requiring no additional hardware. You might want to upgrade to a DAW and standard microphones in the future but it's still good to have a USB microphone in your arsenal. I have one I use with my laptop for mobile recording all the time (mine is a Sampson C01U). I can just plug it in, and the computer automatically recognizes it as an audio interface. Then I'm ready to go. I can make professional sounding recordings for under $100. If you're just getting started in home recording, a USB microphone will allow you to get your feet wet, and make good quality audio recordings without breaking the bank.