A preamble: I\'ve been using PHP for over 8 year every now and then, but never used a framework, only wrote scripts and addons. Mostly I used code generators like CodeCharge Stu
1) Do ZF developers use some kind of prototypes to roll out a basic site quickly?
The Zend Framework is a little too young yet for components in this area, however there is an unofficial PEAR channel. As of March '09 the thought leaders still seem to be debating the best ways to organize everything. I personally am most excited about the domain-driven initiatives as they will be the most robust.
2) Are there some site source codes to be built upon already available?
The best sources right now are the blogs, sites, and repositories of ZF thought leaders. Here's some links to get you started:
Brian here in the comments notes Rob Allen's tutorial. It was the first to really go beyond the basics and is the foundation for his book Zend Framework In Action.
Padraic Brady's blog application tutorial and svn repository has been one of the most complete examples showing how a lot of the components fit together. It's being migrated to an online book called Survive The Deep End but will take some time as he mentions in his blog that he's extremely busy.
Matthew Weier O'Phinney has done a few interesting setups which you can read about and clone from his github repository. The 'bugapp' branch especially in that repo has some interesting techniques. He's been working locally lately so the latest updates are in his blog.
Damien Mathieu has been working on a DRY framework based on best practices.
3) Is there some app generator or minor tool for pages with grids, records etc?
There is a scaffolding-generator as a part of Zend_Tool slated for release in ZF v1.8. It's currently in the incubator, I tried it last week and it works, but there are not many components generated in its current state.
Last week I finally took the time to gather sources together (which includes the Stack Overflow ZF questions feed). I've put them under a Zend Framework tag in Google Reader and will be refining the feed sources over time. In case you'd rather manage them yourself, here is the current OPML.
Best of luck! -Matt
expertseries | Zend Framework | Google Reader