The Error Notebook is just a four column notebook: the first column displays an error you commonly make (spelling, grammatical, usage, documentation, etc.), the second column describes the error or explains why you make that error or the situation in which you usually make the error, the third column displays the correct form, and the fourth column notes the subsection in the Allyn & Bacon Handbook which discusses this error..

Here's an example, with two entries:
 
 

Error	Reason	Correction	ABH Reference
Using "effect" instead of "affect" for the verb "to influence"	Easy to mix these two up, and the noun forms are different. Effect as a verb means to bring about; effect as a noun means a result; affect as a verb means to influence.	The use of computers in the classroom has affected the quality of learning.	Appendix B
"Another reason for using computers are all the information that is available on the Net."	Subject-verb agreement. The subject is singular (reason), but the verb (are) is plural. I think the word "computers" confused me.	"Another reason for using computers is all the information that is available on the Net."	10a

When you get rough and final drafts back, I'll be underlining grammatical, spelling, or citation errors and putting a check in the margin. It's up to you to figure out what's wrong, but I'll be happy to tell you what the problem is. You'll have to use your handbook to understand the error and how to fix it. 

If you don't have very many errors in your papers, then you should write about three pages discussing why you made some of the stylistic and/or organizational choices you made.  In other words, pick a paper or two, find a passage in that paper that you can talk about, and discuss style or organization in that passage.  You may need to find several passages from several papers.