@Sheila ********
I'm in Chiang Mai but this point may well still apply:
I went to the immigration office last week for my exemption extension (two weeks in advance of the original 60 days expiring), and I took everything already printed out or photocopied:
* My TM30 registration of accommodation and my rental agreement with the landlady.
* Main photo and data double page in my passport, which I signed at the bottom of the sheet
* Page of passport with my initial visa exemption stamp from when I entered Thailand, also signed at the bottom of the photocopy
* Plus of course a correct-size photo (4cm x 6cm I think).
In terms of the TM7 application for extension form, you can get it and complete it at the immigration office, or you can download it online, print it, and complete it before you go.
And don't forget the 1900 baht.
Basically, we've found in Chiang Mai at least, that the better prepared you are with the necessary documents printed out, and the photo done, the smoother and less stressful the process.