I would check into purchasing CCM v4.1.3 instead of 3.3.4 (assuming you have the budget for it). Version 4.1.3 is the latest and it's about three or for versions above 3.3.4. There are some better features with 4.1.3. For example, you can't add a person on line two into a conference call on line line on 3.3.4. Our customers complain about this. Version 4.1.3 has the ability.
I would stay away from using IBM servers too. We use HP with no problems. We bought some IBM's to migrate the production environment onto, but we've had nothing but problems.
As for "easy to learn", it depends on many factors. It helps to have a telephony/telecommunications background. It helps to know the Windows server environment even though you don't support it like a windows server (always support it the way Cisco says!). In other words, don't let your server team get their paws on it. :)
It's also helpful to understand networking concepts like layers 1, 2, and 3 of the OSI model. This comes in handy when troubleshooting why a phone won't register.
There is a really good Cisco Press book I recommend. Best Practices for IP Telephony (I can't remember the exact title) We use the Best Practices book on a routine basis. It provides tips on locking the phone switch down against toll fraud internally and externally. Which reminds me...
The one thing that is crucial to understand with IP Telephony is everything related to the "Route Plan". This includes understanding the relationship of the following components: Calling Search Spaces, Routing Partitions, Translation Patterns, Route Patterns, Route Filters, Route Groups, and Route Lists. It becomes even more important to understand their relationships if you are supporting multiple locations on a centralized cluster.
