MS Project - simultaneous work on a project

I have recently started with Microsoft Project. I have a project which has a lot of tasks that needs to completed. Here I am about to install a test architecture for MS Project and Project Server all in 2007. Everything works absolutely fine. But I have a question. Right now we can not work together on different tasks on the project at the same time. Is this normal? I want to track the actual effort done for each task so that we can estimate the time frame the specific task and the hence when the project will be completed.

Although a lot of people over the internet must be talking about the project management tool, I personally go against best practices in Project Management:
- Only one person should work on project management (project manager)

If a project is complex and involves many vertices, we create sub projects that are handled by a project leaders in project (and each planning with Ms Project). In this case we call a project manager to manage the whole. Project leaders at regular intervals, provide dashboards to their project manager. Ms Project helps in the planning of the project manager, and each sub-project has its own task.

I tested it and I wondered if this was possible. I wanted to organize a little, but these are more than simple common projects, they develop almost every line of code separately in a single function. I want to allow more people to see its progress (excluding when he opens a document, it crashes even if I give him the rights of reading). And so for you a project server is useless? Since only one person can enter the info in the tools, both using a stupid windows share and project is accessible only by the project manager (and yes there are still boxes in which the project manager also developed).

We can work together on Ms Project (under 2002 it works like that) with different levels of permissions (I misspoke in my last message):- Project manager, project leaders, team members ... there is also the portfolio manager roles entrusted to the leader or project manager in general. But in a project, assigning only one person is better to manage the project, the project manager (or delegate to handle the administrative part: assistant project manager). It is also recommended for all references in project management. The server is useful for managing very large projects with very large project management, project managers (one for each element in the project) and thousands of others (internal, service providers, fixed...). For projects there is only one project leader (ie no sub element), in my opinion, unnecessary and I think that is not given. But actually Ms Project is one of the best. The recalculation of planning, re-budgeting, the differences and derivatives etc. from the initial planning are excellent. All monitoring costs are simple to manage and more.

This creates a lack of efficiency of work in this way in 2010. There is only one person that can have in writing with the planning. As in the case of large project, it is divided into sub-projects with a PC. But frankly, you forget that all the actors in a project often need access only in consultation with the planning, can be attributed directly to the tasks, as it made the rest and to update themselves in real time (or so with a validation of timesheets in advance by the PC). And on dashboards to trace the progress of sub-projects, don't you think it is better to consolidate auto at master-planning (master schedule). For dashboards, have you heard of OLAP Cubes? Okay, well all this is what you can do with EPM. There's also a web client for searching the schedule, which eliminates the need to deploy MS Project on all positions of the participants who only need to consult, not to change the schedule.