Well, as you know there are four major stages of production.
Stage 1 (or planning) is essentially a lot of meeting and discussions between cast and crew. You should all sit down and read through the script together. After doing that, bounce around ideas/interpretations of the script. A lot of this stage will be quite hectic so ensure you get heaps of notes taken!
Stage 2 (or rehearsals) is where actors rehearse their blocking/staging/delivery, and crew start preparing elements for the show. This is obviously more physical and is a great time to get photos taken. Also, this is a very busy time for the director/actors - so if that is one of your focus areas of stagecraft, jot down notes after EVERY rehearsal!
Stage 3 (or production) is essentially the show and the dress/technical rehearsals prior to that. Try to focus on getting your jobs right in your areas of stagecraft. Don't be as concerned about note taking - at this stage you can afford to do notes in retrospect (but try not to leave them for too long before you make notes)
Stage 4 (or post-production) is where you collect feedback about your performance, and as cast/crew EVALUATE the strengths and weaknesses of the performance and what could have been improved.
Please bear in mind that the show need not be perfect; and that the more catastrophes that occur (such as actors having trouble learning lines, etc), the better - because that will mean you will have more to write on in your SAC and folio.