Add-in Express have published a great number of interesting articles for Excel beginners. To be more specific, Excel beginners who use their All-in Framework .NET to create COM Add-ins, RDTs and Functions Libraries (XLLs and UDFs).
Here is the link to the first article in the series:
http://www.add-in-express.com/creating-addins-blog/2013/09/23/excel-addin-development-application-base-objects/
Enjoy!
Kind regards,
Dennis
VSTO & .NET & Excel 