Hope this can help you:

http://office.microsoft.com/en-us/sharepoint-designer-help/add-a-page-to-a-sharepoint-site-HA010100907.aspx

http://l5randmore.blogspot.in/2008/03/aspx-pages-as-sharepoint-features.html

 

 

For this you can create custom webpart, you can create custom web part using visual studio with sharepoint SDK.

after creating custom web part you can integrate to your sharepoint site.

To know how to create custom webpart follow this link-

http://msdn.microsoft.com/en-us/library/hh228018.aspx