Hi,
for skype integration in .net you can visit this sites:
http://code.msdn.microsoft.com/windowsdesktop/Skype-Integration-in-WPF-6fc42a1e
http://social.msdn.microsoft.com/Forums/vstudio/en-US/a622a3a8-c9ba-41d5-a332-58c341c060ab/can-i-use-skype-api-for-c?forum=wpf
http://www.codeproject.com/Articles/330778/Skypekit-NET
http://www.codeplex.com/site/search?query=Skype
for skype crm integration you can visit this sites:
http://msdn.microsoft.com/en-us/library/hh699721.aspx
http://www.magnetismsolutions.com/blog/roshanmehta/2013/01/21/calling-your-dynamics-crm-customers-with-skype
https://crmskype.codeplex.com/
https://community.dynamics.com/crm/b/crmsoftwareblog/archive/2011/12/15/skype-integration-with-microsoft-dynamics-crm.aspx
http://crmbook.powerobjects.com/system-administration/integrated-technologies/skype-and-lync/
I hope to help you.
bye
Alessandro
Alessandro Graps