The Dramatists Toolkit - The Craft of the Working Playwright
This is a practical guide to being a working playwright
The author discusses such matters as - the building blocks of playwriting; how characters relate to one another; the differences and similarities between musicals and plays; and screenwriting vs playwriting
A valuable resource for all writers, this is a comprehensive guide to playwriting techniques drawing on examples from Shakespeare to Monty Python
To me, 60 pages is incredibly long for one act. I tend to want to write full length plays, but I can't see going much more than 120 pages or so. And timing is all based on your stage direction, your scene changes, setting design and so forth. Heck, act it out while taking breaks for how long you think it takes to set the scene up behind the curtain.
(You could have one stage direction, like "he runs around" that lasts for a good deal of time.)
And you could have a 'waiting for godot'-style play, with back and forth, one sentence at a time, with no scene changes, and yes, the pages go quick went you have more line breaks than dialogue. But I would advise against such writing in most cases.
Yeah, what a waste if your play is like:
John: I asked you first!
Ted: I don't know
Ted: You suck.
Ted: So what!?
With this type of shallow dialogue the pages add up quickly.
To me it's more about word count. I like the range of about 15-30k words for a full length. But again its all about the plot, the style, the setting, and the drama. But hey, I'm no expert.
It really depends. My last full-length clocked in at 67 pages and was 12k words. It ran 1 hour and 45 minutes, there were some visual sequences though. "A page, a minute" is a good guideline for a shorter script, but you need to get longer ones read out-loud to really get a handle on how long it is.