Diary Application In Windows Forms

I want to create a simple diary application where I can add my every day's moment's notes. I have general idea that I can use RichTextBox control to write simple text and a calendar control for navigating previous day's entries. And create a table with nvarchar(max) column to store RichTextBox's content.
But how I will save the content written in RichTextBox control as it is. Means Some text will be heading with bold and italics, some worlds would be written using different fonts and different alignments. How this formatting will remain after saving particular day's entries and showing in next time? Anyone have any idea to store that paragraphs in database? If there is possible then I also want to add images and save it with entered contents but how?  I want general ideas, please.