I want to ask about procedure and the rules to be followed while listening or narrating the puranas and Who can read the Puranas?
The general rules the listener and narrator should have to follow , while listening or narrating the puranas are given Shreemad Bhagvat Maha Purana and in Shiva-MahaPurana (Chapter 7 –Description of worship of the book and the orator) .
Before starting reading or narrating puranas one should do a Sankalpa , Its highlighted that one should listen or narrate the puranas with pure and deep devotion .Only with pure devotion and pure love towards god gives respective outcome of listening or narrating of puranas.
Some of the shlokas describing procedure and the rules to be followed while listening or narrating from Shiva-Maha purana chapter 7
आसमाप्तपुराणं हि समुपोष्य सुशक्तिमान
श्रुणुयाद्भक्तित: शुद्ध:पुराणं शैवमुत्तमं॥६॥
Or a listener who is quite healthy ,should keep fast till the end of the Katha ,getting purified. He should listened to the story of Shiva-Purana with devotion.One should listen to the katha with comfort consuming Ghee or Milk
घृतपानं पय: पानं कृत्वा वा श्रुणुयात्सुखं
फ़लाहारेण वा श्राव्यमेकभुक्तं न वा हि तत्॥७॥
The orator or speaker should consume fruit or take food once in a day and recite the Shiva-Purana.
पलाण्डु लशुनं हिङ्गु गृञ्जनं मादकं हि तत्:
वस्तुन्यामिषसंज्ञानि वर्जयेदय: कथाव्रती॥१२॥
Onion ,Garlic ,asafetida ,carrots and other intoxicating Drinks should not be consumed by the person listening to the katha daily.
गृहस्थच्श्रेद्भ् वेच्छोता कर्तव्यस्तेन धीमता
होम: शुद्धेन हविषाकर्मणस्तस्य शान्तये॥३६॥
In case the listener is a House-Holder , then the wise people should perform homa with pure ghee of cow for Shanti of Katha.
Some of the shlokas describing ,Procedure and the rules to be followed while listening or narrating Shreemad Bhagvat Purana , which are given in Shreemad Bhagvat purana (Mahatmya or glory part) which is originally from Skanda purana vaishnava kanada , bhagvat mahatmya
एषोsप्यत्युत्तम: पक्ष: सप्ताहो बहुसंमत:
Experts say that its best to read Shreemad Bhagvat purana in 7 days.
पुस्तकं च गुरुंचैव पुजयित्वोपचारत:
One should pray and honour Purana book and Guru Ved-Vyasa everyday before reading or listening.
पयसा वा हविष्येण मौनं भोजनमाचरेत
ब्रह्मचर्यमध: सुप्तिं क्रोधलोभदिवर्जनं ॥४४॥
One should only consume milk during those days and maintain celibacy , one should sleep on floor without bed ,and must keep one-self away from anger and lust.
कथान्ते कीर्तनं नित्यं समप्तौ जागरं चरेत
ब्रह्मणान् भोजयित्वा तु दक्षिणाभि: प्रतोषयेत ॥४५॥
After compilation of story , each day kirtan should be performed and at the end of reading or listening of purana. Jagaran (not sleeping whole night while singing songs of god) has to be observed.