You have already learnt the Gurmukhi script for writing Punjabi, the Muharni for Punjabi phonology and some Punjabi vocabulary. This module however is the most important one as you will learn using Punjabi for basic communication with people.
Gurmukhi module is a prerequisite for this module. If you have not mastered the Gurmukhi script and Muharni you are strongly advised to go back to the Gurmukhi script and Muharni modules and practise there thoroughly before returning. In this module you will be expected to have basic skill of reading and writing the Punjabi words.
The reader may note the basic Punjabi syntax which is s-o-v. Barring that the wiki book does not lay any special emphasis on learning of grammar before you can start using Punjabi for basic communication.
This module contains ten pages each devoted to communication in a given situation. Besides this, the first two pages namely 'meeting people' and 'making phone calls' give general exposition on conversation. This module should give you a fair amount of practice. After you are done with this you only require more and more practice to master this fascinating language. You can try your hand at small paragraphs or poems before moving on to full scale essays, novels etc. Links in the References and Further Readings sections will be found useful.