Does working on a work permit help in getting permanent residence status?

It may help as there is a category called Canadian Experience Class which allows people who have worked in Canada for at least one year to seek PR status. The minimum requirements under this category are:

• have at least 12 months of full-time (or an equal amount in part-time) skilled work experience in Canada in the three years before you apply,
• have gained your experience in Canada with the proper authorization,
• meet the required language levels needed for your job for each language ability (speaking, reading, writing and listening),
• plan to live outside the province of Quebec.

The work that you worked in also needs to be in a skilled work category:

• Managerial jobs (NOC skill level 0)
• Professional jobs (NOC skill type A)
• Technical jobs and skilled trades (NOC skill type B)

The program was recently changed and subsumed by Express Entry. A key effect of this change is that now it is extremely helpful to have a valid job offer.