When evaluating an off the shelf package remember to have a look at their software training material. Often this will be a series of online videos (these can be very effective if they have been done well) or a comprehensive FAQ. It is unlikely there will be any face to face opportunity unless its a monster package and would probably be available through a third party. Manuals can be good and usually available as a downloadable pdf but you would be amazed as to how often they don’t get looked at, even for our bespoke software solutions.
Be prepared that the most successful way for your users to train will be an initial face to face workshop where they are introduced to the system and can ask questions. Then let them loose (sometimes on a non critical version) on it. It is at this point in the early cycle of the launch that you will most benefit form a good phone support package where they have access to quick answers to prevent them from losing confidence in the system when they get stuck.
One alternative is to create an expert within the business. Here that individual can benefit from a lower cost third line support package and then disseminate their knowledge throughout the business.
Of course, the better the software training the more expensive, but equally the more effective the outcome will be for your software.