It sounds like you want Non-Secure and Secure pages within the web. Doing this without any third party tools or applications isn't all that difficult.
page explains how to do it in .asp script. The code in the link is easily edited for and number of desired applications.
Users upon login could be directed to a page based on their logon credentials. All usernames and their respective passwords are saved in a database. Users forgetting their passwords could be directed to a non-secure page and use a form to request their password and the password automatically emailed to them.
The link makes refrence to Expression Web but that really matters not as the .asp code sample will run on any server supporting .asp scripting.
A very simple running example of this can be found HERE
Use the first link to try and enter the secured page. Then click the password protected page link. You are taken to a logon.
The examples are very plain and basic but you get the idea.
To my way of thinking doing your own code opens the door for more possibilities.