I wanted to know the number of times a pilot has to refer to his/her checklist for the entire flight (before startup to engine shutdown).
Typically, the checklists in normal operations are:
- External walk around and preflight
- Before start
- Before taxi
- Before take-off
- After take-off
This list is pretty much the same for all aircraft.
Normally, each checklist is only used once at the appropriate time but a wise pilot would re-run a checklist if interrrupted.
For example, you are cleared to start and complete the before start checklist but there is then an unexpected delay before you actually start. You wait for 30 minutes. No need to redo the before start checklist because you did it earlier? No, do it again. Something might have changed.
Simon mentioned a great list of common checklists (of course, keep in mind there are lots of other checklists for emergency situations; fuel dump, engine out, engine fire, hydraulics, etc. etc.)- I would like to address one specific point in your question:
I wanted to know the number of times a pilot has to refer to his/her checklist
I don't mean to be pedantic here, but checklists are always referred to (in other words, they are not memorized). Even the most experienced pilots go through the checklist manually - of course - it takes them quicker to go through each checklist due to their experience but they always refer to it.
I have the most experience with the 737 and on this aircraft, typically the checklists are laminated and on some aircraft placed above the cockpit instrument cluster; in addition some checklists are actually written on the yoke itself:
(image from wikipedia entry on yoke)
The checklists are before takeoff / after takeoff / approach / landing. The little yellow bug (on the right) is to keep track of the items.
During one of my orientation sessions, the instructor reminded me to not do the checklist by memory, you must always refer to the written list.
He then mentioned "in the air force they make us memorize the checklists and do them by memory, but not on civilian aircraft".