How can 2 dev teams work on the same projects.

Sounds like you want to alter the standard security settings in Team Foundation Source Control. The source control system has a very flexible and powerful security model, but you must be careful when making changes here as you could deny everybody permission to the files - including yourself (see http://www.woodwardweb.com/vsts/000158.html for a post I did when I accidentally denied myself permissions to my TFS system). Probably safest to practise this in a Virtual PC version of TFS or in a play project (and make sure you have backups of your TFS databases). Now the health warnings are over, let's get through to the good part :-)

If I understand you correcly, you have one Team project, and then multiple solutions / visual studio projects under that. Your source tree will probably look something like this:-

$/MyTeamProject/
$/MyTeamProject/TeamAProject
$/MyTeamProject/TeamBProject

You will need to create 3 new groups in your active directory config (you may have the groups defined already). TeamA, TeamB and MyTeam (where TeamA and TeamB are members of MyTeam). All all the developers into the appropriate team group.

Next, you need to make sure your developers have access to the Team Project (for work items etc). Right click on "MyTeamProject" in the Team Explorer window and select Team Project Settings, Group Membership... Select the [MyTeamProject]\Contributors group and add your windows group MyTeam to the project contributors. You will also need to make sure that the members of this group have access to Sharepoint and Reporting Services via their seperate admin tools or use something like this (http://go.microsoft.com/fwlink/?LinkId=59385) for easier configuration.

Now, go back to the source control explorer. By default, everyone in Contributors gets developer access to the source control repository from the team project level down (i.e. $/MyTeamProject), however you can modify this. This is the point where my health warnings kick in...

Right click on $/MyTeamProject/TeamAProject in Source Control Explorer and select Properties then the Security tab.

You can see the security permissions here - all the options will be grayed out apart from "Inherit securty settings". If you un-check this all the secuirty options will be removed. BEFORE YOU PRESS OK, make sure that at least you have given the Project Administrators group and the [Server]\Team Foundation Administartors group Allow permissions on everything - otherwise nobody will have any rights on this mode in source control - including yourself...

In your case, you want to give allow permissions on everything to Build Service, Project Administrators, [Server]\Service Accounts and [Server]\Team Foundation Administrators. Your should give the Contributors and Readers groups the same permissions which are just Allow on the Read permission. Next you need to add the windows group created for TeamA and give them the permissions that Contributors used to have (i.e. Allow on Read, Check Out, Check In, Label, Lock). You will want to repeat the procedure for all the projects that TeamB own.

To make life easier, it might make sense to have all the projects for TeamA under one folder at the root of source control and the same for TeamB - that way the projects created under these folders will be able to inherit permissions.

Hope that makes sense,

Martin.