Here are several forklift training manual resources you can use for free to either adapt or develop your own.
Forklift Operator Training Handbook
Download the forklift operator training manual
Forklift Training manual from San Jose State University
This forklift training publication was published by San Jose State University is design for its own forklift operators, however there is plenty of excellent material in that can be used to put together your own training manual. Includes topics cover such as Moving Loads, Driving A Forklift, Setting Down A Load, Common Forklift Pitfalls and Forklift Hazards among other topics.
Guide to Forklift Operator Training