I'm about to create a new application - somewhat like a CRM. I'm thinking it would be best to diagram out all the tables/fields before I begin...but not sure what is the best way to do so? Are there tools in VS? MSSMS? Something else? I want to quickly and thoroughly create the database the application will use for its back-end.
I quite like to use Microsoft Visio to map this sort of stuff out.
Or even better - a wipeboard!
This http://msdn.microsoft.com/en-us/library/ms171971%28VS.80%29.aspx article explains pretty well how to create database diagrams using Microsoft SQL Management Studio. You can download SQLMS here: http://www.microsoft.com/express/Database/
The nice thing about this approach is that your diagram is also your database so you don't have to create the diagram and then create the database, you can get them both done at the same time.
You can do this inside Visual Studio. Just set up a Database and in the Server Explorer, create a new diagram. The way to do this differs in different VS Versions.
Another approach would be to use the Management Studio Express
You can get this one here.