Ed,
Account Determination Groups tends to be a hurdle for most customers that haven't used them before, but they key to understanding them seems to realize that, compared to certain customers current processes, account determination groups were designed to handle significantly more complex scenarios.
Fundamentally, they exist to provide consistency for financial postings in an environment with multiple sets of books. What this can do is only have the staff entering transactions have to know the Account Determination Group, but for two (or more) different sets of books, the exact same transaction can actually hit two (or more) different G/L Accounts in order to meet reporting requirements. Or, for example, if staff handle transactions for multiple companies, they do not have to know that G/L Account XXXXXX is applicable to the Company A, but G/L Account YYYYYY is the one to use for a different Company B. They just have to know the appropriate Account Determination Group and the postings will happen correctly.
We had the usual series of questions with customers that only operated in a single country with one chart of accounts ("why can't I just enter a G/L account?"). To make their lives easier, we specified the Account Determination Groups with the same ID as the G/L they were assigned to. This works (provided you don't expect to expand into multiple charts of accounts, otherwise you’ll have to change everything)
As for Project Management, the key to understanding that is that there is a distinct separation between the different portions of it. For example, in Customer Projects with Sales Integration, Revenue is based on the Sales Orders – it is not controlled on the Project. Likewise, the Costs must be linked to Sales Orders to correctly recognize.
As far as the operational aspects of Project Management, staffing seems to be a major one. To ensure the smoothest process, Projects must be staffed correctly, and the start/end dates of tasks must be set correctly. Otherwise, people will be trying to enter time and will not find the tasks they need on their time sheet.
It's a pretty aggressive time frame, but i think it's doable - they key is to reduce confusion as much as possible early in training.