Your film should be delivered to the lab in taped light-safe cans. (Tape around the rim of the can both seals the can, and is an industry-standard "flag" that the can contains exposed, undeveloped film.)
Each can should be clearly labeled with the following items (some of this information will already be printed on the film's factory label-- just make sure you don't cover or mark over it!)
In our experience, far too many student filmmakers neglect to number their camera rolls. Assigning each roll a unique number will save you (and us, and your negative cutter) a lot of confusion. If you don't do it, we WILL do it for you... but probably not in the order you would want. So better to do it yourself.
You should also provide us with copies of your camera reports, or otherwise let us know if you expect any problems with your negative due to known camera malfunctions, severe exposure or focus problems, etc.
And of course, you will need to let us know your name, address, telephone number
(two numbers are better), payment information, and so forth. If you are mailing
your negative to us (or sending it by courier, or having a friend drop it off),
you will need to include a clearly printed letter with your name, address, and
telephone and credit card numbers, a description of exactly what materials and
quantities you are sending us, and what you want done with them.