Congrats on starting residency!
1. Cervical checks are very subjective and therefore a great source of anxiety for interns. I suggest you check your fingers against a centimeter ruler to see 1) how wide is 1 finger (generally one finger in the cervix means 1-2 cm dilation), 2) how wide is 2 fingers (generally two fingers is 3 cm), and most importantly have someone check behind you with every exam the first couple of weeks. You'll get the dilation down first, then the effacement, and last will be station. If you're in a busy program (like I was), the senior residents may not be available EVERY time you see a patient, so if there is an experienced L&D nurse, then have them check behind you as they'll be able to give you feedback. Don't worry, inevitably (based on having many an intern come and go), after a couple of weeks you'll have a great sense of comfort.
2. The best preparation involves 1) reading the text, 2) practicing on a simulator, and 3) going through a shoulder a couple of times. Again, don't be alarmed as you should have a PGY-3 or PGY-4 and/or attending during deliveries these first few months and they'll step in to help out. The first couple of times, it might be well worth your time to watch and see what happens. Some PEARLS from having seen my fair share of shoulders:
1. Realize its a shoulder and stop the traction for a second
2. Immediately ask for extra nurses, OB's, anesthesia, and NICU
3. Ask the nurse what time it is exactly
4. McRoberts
5. Suprapubic
6. Go to your manuever of choice...
7....
8...
9. Before writing your note or the nurse writing hers, get together, debrief, and make sure all events/times are accounted for, questions answered, and correct information gathered for the note.
Hope this helps you.