You can have the Sitefinity Web Application in a source control system in the same way as with any standard ASP.NET application. You can put all the code in a source control system, if you need to do custom development for your Sitefinity application. In your development process, you also have the option to share the database or to employ local copies for each developer.
Best practices advice to exclude the configuration files from the project source control, so they will not need to be checked out. Anyway, if you want to put the configuration files in source control system, a better approach for each developer is to check out all configuration files before start working with the project.