Other things...
1. Inevitably in a musical, when it comes to a song, people are looking at three different versions of it - the normal script, the conductor's score, and the vocal book (usually in the back of a script, with only the singing parts). Take the time to create a chart for yourself of all pertinent info you can quickly access. I usually put a column first with the song number (orchestra members will flip to #5 or #10a for example), then the Song Title, script page, vocal book page, and score page. I also like to include which characters are in the number, too, for another quick reference. Saves a LOT of time as people jump from song to song, to keep everyone on track.
2. With musicals moreso than other shows, I find it extremely useful to make a chart of which people are on for exactly which pages, not just by scene, to facilitate costume changes - especially when someone changes an entire character (bit parts for the chorus, I'm thinking).
Erin