Authentication and authorization - new to security

Need to develop a Web application that will be used to authenticate and authorize internal and external users to log and then re-route to web applications for the organization. The login application should be able to provider smooth integration with any future applications that needs a secured authentication.

Should I be using WIF - Claims based Identity/ADFS or asp.net Role membership provider to develop this app.?  Or is there any other approach which will help achieve this?

Here are some good articles that will help you understand the types of Authentication and Authorization, as well as how to implement them and when or where to use them:

http://aspalliance.com/907

http://wiki.asp.net/page.aspx/43/authentication-and-authorization/

http://www.careerride.com/ASP.NET-Authentication-Authorization-Questions.aspx

http://www.c-sharpcorner.com/UploadFile/lmoningi/AuthenticationAndAuthorizatio11252005233533PM/AuthenticationAndAuthorizatio.aspx

Hope this helps.

You can also refer the following link below to get started with asp.net security stuffs:

http://www.asp.net/web-forms/security