A major part of Chapters 8 – 14 is Huck’s adventure on the WALTER SCOTT. Huck mentions that he wishes the Widow Douglas could know about his efforts to save the men on the wreck. Pretend that you are Huck and write a letter to the Widow, explaining the situation and what you did about it.

Can someone give me a few ideas on how I could start this out. Please? Thanks.

"write a letter to the Widow, explaining the situation and what you did about it."

That seems pretty clear. If you need to review Huck's language (vernacular), then you should re-read those chapters and make note of his vocabulary and syntax. If you need reminding of what happened in those chapters, use the appropriate sections here:
http://www.sparknotes.com/lit/huckfinn/