Trying to setup simple membership area

I have a site i am developing. The client will need to be able to create new users (all logged in users have the exact same access) and then those users will login and have access to a "Training Area of the site" That should not be accessible to normal users. The training area will have some pages, but all posts will be under the main category (called "Training") with sub categories. I can not figure out how to do this (I figure it must be something simple), basically i just need to have a login button that takes the user to a login page. Once logged in they will be taken to an area that has additional menus for Training and posts/pages.. Please let me know if you can help me out. Thanks!