First things first: you need to figure out which level of lesson fits with your current level of Mandarin experience. This will allow you to easily choose classes that won't be too difficult (or too easy).
We have a handy Placement Test that will let you know where you are amongst ChinesePod's five levels - newbie, elementary, intermediate, upper intermediate, and advanced.
All you need to do is:
A. Choose Character Set: Pinyin, Traditional, or Simplified
B. Choose Test Length: Short, Medium, or Long. Keep in mind, the longer the test, the more accurate your placement will be!