The FAA publication Basic Helicopter Handbook is
Although still useful, you should know this publication has
been superceded by the Rotorcraft Flying Handbook,
The Robinson R-22 is the most popular light
piston training helicopter. It has also seen its
share of controversy, and a good deal of scrutiny
by the FAA. Some documents related to this helicopter
The Usenet Newsgroup
has a number of experienced pilots contributing information and
answering questions. They've also retold some stories that
make for interesting reading.
Click here to read some of them.
A story about a collective "excursion" can be found