For project documentation, either One Note or Word would work fine in my opinion. I would got with Word for more formal documents like statement of work, change requests and sign off. If you need things like skills matrix, Excel works just fine or Word with tables.

I wouldn't worry so much about what product -- remember one of the key things as a project manager is communication. You are the hub of the communication in the team -- your communicate information both to the team as well as act as the communication conduit to the sponsor and sponsoring organization.