You mean:
a): read and understand the report write out by PT
or
b): make PT write out the timing report
For a): You just need first make sure you undertand the basical timing calculation method and what is the mean of some keyword in PT report. Such as: you need know what is setup/hold violation, why there will be a setup/hold violation, what does transition, load, fanout, slack, startpoint, endpoint means and how the delay values are calculated out.
For b): you'd better use the follow step in pt_shell:
1): help report)*
2): man report_timing / man report_?????
Thanks.