Spending up to $100
  1. If you're doing a solo podcast go with a USB microphone.
    Amazon sells a bunch of different ones. Go with one you're comfortable springing money on. Check reviews, but don't get overwhelmed with choice. Grab one and go. Upgrades won't be needed for a long while. Blue Microphones Snowball iCE Condenser Microphone, Cardioid https://www.amazon.com/dp/B006DIA77E/ref=cm_sw_r_cp_api_1eQ5xb4PJPFTA
  2. If you're doing an interview type podcast get a sound recorder.
  3. Free Software: Audacity.
    There is a free version of adobe Audition 3.0 that is available completely free but hard to find. (Windows only for this one)