Two types of training are provided by the Tiny company and its partners:
Technical training in OpenERP: the objective of this intensive training is to enable you to develop your own modules by modifying and adapting the existing ones. It covers the creation of new objects, menus, reports and workflows, and also of interfaces with external software. It lasts for five days and is designed for IT people.
User training: this enables you to be productive as rapidly as possible in the use of OpenERP. All of the modules there are detailed with concrete examples and different exercises. For the sake of realism, the training uses data for a fictitious company. This training also lasts for five days. It is designed for those responsible for an ERP project, who will then be capable of training employees internally.
Tiny's training calendar is available on the official OpenERP site at http://www.openerp.com/services/training-schedule. The training is delivered in either French or English, depending on the course.
Both Tiny, the creators of OpenERP, and the OpenERP partners can also provide customized training. This, although more expensive, is focused on your own needs.
Your training needs depend on the type of deployment you have chosen. If you have opted for a SaaS development, technical training is not very useful.
In summary, you should arrange both user training and self-paced training (perhaps based on this book series) if you can. Technical training is strongly advised if you see yourselves developing your own modules. Although it is not obligatory, it gives you quite a time advantage in any serious OpenERP engagement.