Every ERP implementation involves various documents evolving at different stages of implementation. Broadly, these stages are Proposal, Service Agreement, Initiation, Solution, Training, and Sign-Off. Every organization follows its documentation process, and some of them will be shared by the ERP provider. Having implemented ERP for many years now, I can tell you that you will easily become acquainted with these documents during the course of implementation. However, the real challenge lies in monitoring requirements and data.
In the meantime, you can consolidate requirements from all functions and have them documented in a format that can be easily tracked by you. This will help you in the later stages of implementation. You can also prepare and correct all employees' data as this is quite time-consuming.
Regards,
Murali