What is the TM 30 form requirement for extending a tourist visa in Thailand?

Could I ask you to clarify some things about TM 30 for me? If I arrive on tourist visa (60 days) and later ask for a 30 day extension in Chiang Mai, I will probably need this form, right? So:

1. Do I only need to obtain it from the last accommodation before applying, or I need to ask for it in every hotel where I stayed during these 60 days, and arrive at Immigration Bureau with a pile of these forms?

2. What if some days are not covered by TM 30, e.g. I stay at my friend's for the weekend, or at a campsite?