I'm travelling to New York in July and was looking at going to a Broadway musical. Tickets are more expensive than I thought for the major Broadway shows. I understand there are same-day ticket booths that often do cheap tickets. Where do I go and what do I need to know (are tickets available for most shows? Or not many? What sort of discount? What time do I need to get there, etc) ?
This is where you want to go. TKTS booth located in the middle of Times Square will give a discount up to 50% on the shows currently playing on Broadway. Although I have to warn you that more popular shows and popular times are likely not to be available. What time do you need to get there will depend on the time of the show you want to see and the day of the week. Fridays and the Weekend tend to be the most popular.
In addition to the TKTS booth that karlson has talked about some of the theatres have standby tickets available for that night. I was in NY a couple of months ago and got a "Rush Ticket" to see the spiderman musical from the theatre box office for $39.