Setting Security Levels in Access 2007

I have created a split database in Access 2007 and need to set user level security. I don't want the users to have access to any of the tables 开发者_如何转开发or queries etc. I've created a form so when the database is opened it automatically opens where the user can choose an application to run. How would I go about setting the security levels for each user?

I found the below links using Google. Bit sarcy but it would always be my first port of call without further info or details in a given question showing research already done.

MS1, MSblogentry